Overview This comprehensive course on Front End Web Development Training for Everyone will deepen your understanding on this topic. After successful completion of this course you can acquire the required skills in this sector. This Front End Web Development Training for Everyone comes with accredited certification from CPD, which will enhance your CV and make you worthy in the job market. So enrol in this course today to fast-track your career ladder. How will I get my certificate? You may have to take a quiz or a written test online during or after the course. After successfully completing the course, you will be eligible for the certificate. Who is This course for? There is no experience or previous qualifications required for enrolment on this Front End Web Development Training for Everyone. It is available to all students, of all academic backgrounds. Requirements Our Front End Web Development Training for Everyone is fully compatible with PC's, Mac's, Laptop, Tablet and Smartphone devices. This course has been designed to be fully compatible with tablets and smartphones so you can access your course on Wi-Fi, 3G or 4G. There is no time limit for completing this course, it can be studied in your own time at your own pace. Career Path Learning this new skill will help you to advance in your career. It will diversify your job options and help you develop new techniques to keep up with the fast-changing world. This skillset will help you to- Open doors of opportunities Increase your adaptability Keep you relevant Boost confidence And much more! Course Curriculum 8 sections • 33 lectures • 06:19:00 total length •Introduction: 00:13:00 •Understanding HTML5 Popular Element: 00:11:00 •Events: 00:09:00 •Geolocation: 00:10:00 •Drag and Drop: 00:14:00 •CSS: 00:13:00 •Main Element: 00:14:00 •Demonstrating Box Model: 00:10:00 •Combination Selector Example: 00:05:00 •Media Queries: 00:11:00 •Inspect Element: 00:07:00 •CSS Transition: 00:12:00 •Animations: 00:09:00 •Java Script Data Types: 00:10:00 •Console: 00:10:00 •Advance Java Script: 00:12:00 •Singleton Pattern: 00:14:00 •New User Console: 00:13:00 •Promises: 00:15:00 •J Query: 00:09:00 •Selectors: 00:14:00 •Keyboard Events: 00:13:00 •Attribute and Value: 00:15:00 •Bootstrap: 00:13:00 •Fluid Container: 00:17:00 •Pagination: 00:13:00 •Bootstrap Grid System: 00:15:00 •Portfolio Page: 00:15:00 •Portfolio Title: 00:14:00 •Services: 00:12:00 •Navbardark: 00:10:00 •Contact Page: 00:07:00 •Resource - Front End Web Development Training for Everyone: 00:00:00
Overview Gain the necessary skills and knowledge to become a competent Transport and Logistics Manager, and learn fundamental project management and supply chain management principles, with the complete Transport & Logistic Management course. Designed by industry experts, this Transport & Logistic Management training course will guide you through every stage of your career, from understanding how the supply chain works, to the elements of a strong and efficient supply chain. You'll also learn about procurement and the relationship between supply chain and logistics management. Fast track your career today by learning specialist industry skills, and ensure your complete career progression, with a recognised qualification in transport and logistics management. Why buy this Transport & Logistic Management? Unlimited access to the course for forever Digital Certificate, Transcript, student ID all included in the price Absolutely no hidden fees Directly receive CPD accredited qualifications after course completion Receive one to one assistance on every weekday from professionals Immediately receive the PDF certificate after passing Receive the original copies of your certificate and transcript on the next working day Easily learn the skills and knowledge from the comfort of your home Certification After studying the course materials of the Transport & Logistic Management you will be able to take the MCQ test that will assess your knowledge. After successfully passing the test you will be able to claim the pdf certificate for £5.99. Original Hard Copy certificates need to be ordered at an additional cost of £9.60. Who is this course for? This Transport & Logistic Management does not require you to have any prior qualifications or experience. You can just enrol and start learning. Prerequisites This Transport & Logistic Management was made by professionals and it is compatible with all PC's, Mac's, tablets and smartphones. You will be able to access the course from anywhere at any time as long as you have a good enough internet connection. Career path As this course comes with multiple courses included as bonus, you will be able to pursue multiple occupations. This Transport & Logistic Management is a great way for you to gain multiple skills from the comfort of your home. Course Curriculum Transport Management An Introduction to Successful Transport Management 00:20:00 The UK's Travel Infrastructure - Road and Rail 00:10:00 Road Freight and Transport Management 00:30:00 Passenger Road Transport and its Management 00:30:00 Rail and Transport Management 00:15:00 Transport Management for Ports and Inland Waters 00:15:00 Transport Management for Airlines 00:10:00 Trends, Challenges and Best Practice in Transport Management 00:10:00 Transport Management and Health and Safety 00:10:00 SAP Transportation Management ECC TM EWM Shipment Integrated Scenario 00:30:00 SAP Transportation Domestic Scenario 00:22:00 SAP Transportation Management (TM) Integrated Scenario 00:15:00 TM Overview + End to End Process Flow 00:43:00 SAP TM Uncontrolled Shipment Scenario 00:28:00 SAP TM - Air Way bill ID Generation 00:26:00 Effective SAP TM for perfect order fulfillment! 00:56:00 Mock Exam Mock Exam- Transport & Logistic Management 00:20:00 Final Exam Final Exam- Transport & Logistic Management 00:20:00
Overview Uplift Your Career & Skill Up to Your Dream Job - Learning Simplified From Home! Kickstart your career & boost your employability by helping you discover your skills, talents, and interests with our special Advanced Linear Programming Course. You'll create a pathway to your ideal job as this course is designed to uplift your career in the relevant industry. It provides the professional training that employers are looking for in today's workplaces. The Advanced Linear Programming Course is one of the most prestigious training offered at Skillwise and is highly valued by employers for good reason. This Advanced Linear Programming Course has been designed by industry experts to provide our learners with the best learning experience possible to increase their understanding of their chosen field. This Advanced Linear Programming Course, like every one of Skillwise's courses, is meticulously developed and well-researched. Every one of the topics is divided into elementary modules, allowing our students to grasp each lesson quickly. At Skillwise, we don't just offer courses; we also provide a valuable teaching process. When you buy a course from Skillwise, you get unlimited Lifetime access with 24/7 dedicated tutor support. Why buy this Advanced Linear Programming ? Lifetime access to the course forever Digital Certificate, Transcript, and student ID are all included in the price Absolutely no hidden fees Directly receive CPD Quality Standard-accredited qualifications after course completion Receive one-to-one assistance every weekday from professionals Immediately receive the PDF certificate after passing Receive the original copies of your certificate and transcript on the next working day Easily learn the skills and knowledge from the comfort of your home Certification After studying the course materials of the Advanced Linear Programming there will be a written assignment test which you can take either during or at the end of the course. After successfully passing the test you will be able to claim the PDF certificate for free. Original Hard Copy certificates need to be ordered at an additional cost of £8. Who is this course for? This Advanced Linear Programming course is ideal for Students Recent graduates Job Seekers Anyone interested in this topic People already work in relevant fields and want to polish their knowledge and skills. Prerequisites This Advanced Linear Programming does not require you to have any prior qualifications or experience. You can just enrol and start learning. This Advanced Linear Programming was made by professionals and it is compatible with all PCs, Macs, tablets, and smartphones. You will be able to access the course from anywhere at any time as long as you have a good enough internet connection. Career path As this course comes with multiple courses included as a bonus, you will be able to pursue multiple occupations. This Advanced Linear Programming is a great way for you to gain multiple skills from the comfort of your home. Advanced Linear Programming Unit 01: Introduction 01:25:00 Unit 02: Constraints like >= 00:47:00 Unit 03: Mixed Type of Constraints 01:00:00 Unit 04: Mixed Constraints, Multiple Solutions 00:36:00 Unit 05: Mixed Constraints Again, A Good Practice Problem 00:26:00 Unit 06: All Constraints of '=' type. No slack, Surplus or Artificial Variables 00:13:00 Unit 07: Constraints like >=, But Great Simplification 00:47:00 Unit 08: The Concept of Simplifying the Problem 00:28:00 Unit 09: Degeneracy Explained 00:45:00 Unit 10: Two-Phase Method 00:34:00 Unit 11: Sensitivity Analysis Explained with an Example Part 01 01:01:00 Unit 12: Sensitivity Analysis Explained with an Example Part 02 00:42:00 Unit 13: Duality in Linear Programming Part 01 00:15:00 Unit 14: Duality in Linear Programming Part 02 00:23:00 Unit 15: Solver tool 00:29:00 Unit 16: A Production Scheduling Problem for Formulation 00:26:00 Unit 17: An Infeasible Problem 00:14:00 Unit 18: Mobile Apps for Linear Programming Problem 00:21:00 Unit 19: Online Solutions 00:17:00 Additional Materials Resource - Advanced Linear Programming Order Your Certificate Order Your Certificate QLS
Our Aim Is Your Satisfaction! Offer Ends Soon; Hurry Up!! Are you looking to improve your current abilities or make a career move? Our unique Front-End Web Development (HTML, CSS, & Bootstrap) course might help you get there! Expand your expertise with high-quality training - study the Front-End Web Development (HTML, CSS, & Bootstrap) course and get an expertly designed, great-value training experience. Learn from industry professionals and quickly equip yourself with the specific knowledge and skills you need to excel in your chosen career through the Front-End Web Development (HTML, CSS, & Bootstrap) online training course. The Front-End Web Development (HTML, CSS, & Bootstrap) course is broken down into several in-depth modules to provide you with the most convenient and rich learning experience possible. Upon successful completion of the Front-End Web Development (HTML, CSS, & Bootstrap) course, an instant e-certificate will be exhibited in your profile that you can order as proof of your skills and knowledge. Add these amazing new skills to your resume and boost your employability by simply enrolling in this course. This Front-End Web Development (HTML, CSS, & Bootstrap) training can help you to accomplish your ambitions and prepare you for a meaningful career. So, join us today and gear up for excellence! Why Prefer Us? Opportunity to earn a certificate accredited by CPDQS. Get a free student ID card!(£10 postal charge will be applicable for international delivery) Innovative and Engaging Content. Free Assessments 24/7 Tutor Support. Take a step toward a brighter future! *** Course Curriculum *** Here is the curriculum breakdown of the Front-End Web Development (HTML, CSS, & Bootstrap) course: Section 01: Welcome 1.1 Intro 1.2 Install the Tools and Get Started Section 02: HTML 5 2.1 Intro to HTML 2.2 What is HTML 2.3 Start a New HTML File & Use Tags 2.4 Header Tags 2.5 Edit Text 2.6 Links 2.7 Images 2.8 Lists 2.9 Challenge 1 Section 03: CSS 3 3.1 CSS Intro 3.2 Add CSS Styles 3.3 Classes and IDs 3.4 Borders 3.5 Sizing 3.6 Padding and Margin 3.7 Text Styles 3.8 DIVs 3.9 Postioning 3.10 Hover 3.11 Easily Center Elements 3.12 Fonts 3.13 Challenge 3.14 CSS Outro Section 04: Bootstrap 4.1 Intro to Bootstrap 4.2 Install Bootstrap 4.3 Indenting and Containers 4.4 The Grid System 4.5 Images 4.6 Buttons 4.7 Challenge 3 4.8 Bootstrap Outro Section 05: Project 1 - Design a Landing Page 5.1 Landing Page Intro 5.2 Sketch Your Landing Page 5.3 The Top Section 5.4 Polish the Top Section 5.5 Adding Images 5.6 The Main Points Section 5.7 Collecting Emails With an Opt-In Form 5.8 Challenge 4 5.9 Landing Page Outro 6.1 Business Site Intro 6.2 Sketch Up 6.3 Using Fancy Font Logo 6.4 Carousel Basics 6.5 Carousel Extras 6.6 Text on Images 6.7 Phone Number Icon 6.8 Google Maps 6.9 Font Awesome 6.10 Challenge 4 6.11 Business Site Outro Section 06: Project 2 - Business Website 7.1 Intro 7.2 Portfolio Sketch 7.3 Jumbotron 7.4 Nav Bar 7.5 Panels 7.6 Challenge 5 7.7 Portfolio Outré Section 07: Project 3 - Portfolio 8.1 Hosting 8.2 Bluehost 8.3 Uploading 8.4 Tips 8.5 Hosting Outro Assessment Process Once you have completed all the modules in the Diploma in Front-End Web Development (HTML, CSS, & Bootstrap) course, you can assess your skills and knowledge with an optional assignment. Our expert trainers will assess your assignment and give you feedback afterwards. CPD 10 CPD hours / points Accredited by CPD Quality Standards Who is this course for? Anyone interested in learning more about the topic is advised to take this Front-End Web Development (HTML, CSS, & Bootstrap) course. This course is open to everybody. Requirements You will not need any prior background or expertise to enrol in this course. Career path After completing this course, you are to start your career or begin the next phase of your career. Certificates CPD Accredited Certificate Digital certificate - £10 CPD Accredited Certificate Hard copy certificate - £29 If you are an international student, then you have to pay an additional 10 GBP as an international delivery charge.
Imagine crafting the digital face of the future with the 'Complete Web Development' course, a compendium that transforms novices into web virtuosos. Your journey will commence with the basics, gradually unfolding into the intricate layers of web construction. Within this course lies the key to mastering the pillars of web creation - HTML5 and CSS3, the canvas and palette of the internet. As you advance, you'll wield the power of JavaScript and jQuery to breathe life into static pages, turning them into interactive experiences that captivate users worldwide. Embark on a quest to weave responsive designs with Bootstrap 4, managing content seamlessly through WordPress, and constructing robust back-ends with PHP and MySQL. The course doesn't just end with creating web pages; it empowers you to integrate APIs, adding endless possibilities to what you can achieve. With the addition of Python and advanced HTML5 & CSS3 features, your skill set will be both in-depth and versatile. As the final module approaches, you'll already be contemplating the numerous doors now open to you, equipped with the knowledge to walk through any. Learning Outcomes Construct and style web pages using HTML5 and CSS3. Implement interactivity with JavaScript and jQuery. Develop responsive layouts with Bootstrap 4 and manage content via WordPress. Design dynamic back-end functionalities using PHP and MySQL. Incorporate APIs for enhanced web capabilities and apply advanced programming with Python. Why choose this Complete Web Development course? Unlimited access to the course for a lifetime. Opportunity to earn a certificate accredited by the CPD Quality Standards after completing this course. Structured lesson planning in line with industry standards. Immerse yourself in innovative and captivating course materials and activities. Assessments are designed to evaluate advanced cognitive abilities and skill proficiency. Flexibility to complete the Complete Web Development Course at your own pace, on your own schedule. Receive full tutor support throughout the week, from Monday to Friday, to enhance your learning experience. Who is this Complete Web Development course for? Beginners eager to embark on web development. Creatives aspiring to translate designs into web formats. Entrepreneurs looking to build and manage their websites. Career changers venturing into the tech industry. Hobbyists interested in learning coding and web technologies. Career path Web Developer: £24,000 - £50,000 Front-End Developer: £26,000 - £47,000 Back-End Developer: £25,000 - £55,000 Full-Stack Developer: £30,000 - £60,000 WordPress Developer: £23,000 - £50,000 Python Developer: £28,000 - £70,000 Prerequisites This Complete Web Development does not require you to have any prior qualifications or experience. You can just enrol and start learning.This Complete Web Development was made by professionals and it is compatible with all PC's, Mac's, tablets and smartphones. You will be able to access the course from anywhere at any time as long as you have a good enough internet connection. Certification After studying the course materials, there will be a written assignment test which you can take at the end of the course. After successfully passing the test you will be able to claim the pdf certificate for £4.99 Original Hard Copy certificates need to be ordered at an additional cost of £8.
The course 'Learn Spring & Angular Material with a Full Web Application' provides comprehensive training in building a full-stack web application using Spring for the backend and Angular Material for the frontend. Participants will learn how to set up and run the application, model the application using UML, build the backend REST API with Spring Boot, and create the frontend components using Angular Material design. Learning Outcomes: Understand the purpose and content of the course, and the technologies used in the web application development. Set up and configure the application, including the backend with Spring Boot and the frontend with Angular Material. Model the application using UML to design its architecture effectively. Develop the backend REST API with Spring Boot, incorporating Swagger for API documentation. Build the frontend components with Angular Material design, including Login, Signup, and TODO-LIST components. Implement API services using Swagger API documentation and create services for the application. Use Angular Guards for securing routes and configure routing for the frontend application. Conclude the course with a comprehensive overview and guidance on what to explore next in web application development. Why buy this Learn Spring & Angular Material with a Full Web Application? Unlimited access to the course for forever Digital Certificate, Transcript, student ID all included in the price Absolutely no hidden fees Directly receive CPD accredited qualifications after course completion Receive one to one assistance on every weekday from professionals Immediately receive the PDF certificate after passing Receive the original copies of your certificate and transcript on the next working day Easily learn the skills and knowledge from the comfort of your home Certification After studying the course materials of the Learn Spring & Angular Material with a Full Web Application there will be a written assignment test which you can take either during or at the end of the course. After successfully passing the test you will be able to claim the pdf certificate for £5.99. Original Hard Copy certificates need to be ordered at an additional cost of £9.60. Who is this course for? This Learn Spring & Angular Material with a Full Web Application course is ideal for Students Recent graduates Job Seekers Anyone interested in this topic People already working in the relevant fields and want to polish their knowledge and skill. Prerequisites This Learn Spring & Angular Material with a Full Web Application does not require you to have any prior qualifications or experience. You can just enrol and start learning.This Learn Spring & Angular Material with a Full Web Application was made by professionals and it is compatible with all PC's, Mac's, tablets and smartphones. You will be able to access the course from anywhere at any time as long as you have a good enough internet connection. Career path As this course comes with multiple courses included as bonus, you will be able to pursue multiple occupations. This Learn Spring & Angular Material with a Full Web Application is a great way for you to gain multiple skills from the comfort of your home. Course Curriculum Unit 01: Introduction Module 01: Why this course? 00:02:00 Module 02: What will you learn in the course? 00:02:00 Module 03: Application demo 00:06:00 Unit 02: Application resources Module 01: How to setup and run the application 00:06:00 Unit 03: The application Module 01: About the course application 00:02:00 Module 02: Used Technologies 00:02:00 Module 03: Modeling the application (UML) 00:02:00 Module 04: The backend architecture 00:07:00 Module 05: The frontend architecture 00:03:00 Unit 04: The backend: REST API Module 01: Create a new spring boot project 00:05:00 Module 02: Configure the project 00:02:00 Module 03: Coding the REST API 00:37:00 Module 04: Adding the Swagger configuration 00:06:00 Module 05: Generating the API documentation 00:15:00 Unit 05: The frontend: Angular material design Module 01: Create a new angular project 00:08:00 Module 02: Configure the project 00:02:00 Module 03: Generate the API services using the Swagger API Doc 00:11:00 Module 04: Create the components 00:03:00 Module 05: Create Login / Signup components 00:15:00 Module 06: Create the TODO-LIST component 00:10:00 Module 07: Create the services 00:06:00 Module 08: What is and Why a Guard? 00:03:00 Module 09: Add and Configure the Routing 00:04:00 Unit 06: General conclusion Module 01: What comes next? 00:01:00 Assignment Assignment - Learn Spring & Angular Material with a Full Web Application 00:00:00
If you've ever wondered how websites come to life in your browser, this Front End Web Development Training is your ideal introduction. Whether you're new to coding or brushing up on your knowledge, this course walks you through the essential languages of the web—HTML, CSS, and JavaScript—with clarity, structure, and a touch of digital charm. You’ll gain insight into how websites are built, styled, and made interactive, all from the comfort of your own screen. Built with beginners in mind but welcoming to all curious minds, the course breaks down web development into manageable, engaging sections. It’s tailored to help you understand the building blocks of the internet without overwhelming jargon or confusing detours. From creating simple layouts to adding life with animations and scripts, each module nudges you further into the world of modern web design. If your goal is to confidently understand what goes into building a page, this training might just become your favourite browser tab. Learning Outcomes: Understanding of the complete front-end development process Knowledge of cascading style sheets and transitions Ability to work with advanced JavaScript features Familiarity with JQuery and selectors Understanding of Bootstrap and grid system for responsive design The Front End Web Development Training for Everyone is a comprehensive course designed to provide individuals with the skills and knowledge needed to develop professional front-end websites. This course covers a range of topics, including cascading style sheets, advanced JavaScript, JQuery, Bootstrap, and grid system. Participants will also learn how to create portfolio pages and other interactive designs. This course is suitable for anyone who wants to learn front-end web development, including beginners and professionals who want to expand their skills. With this course, participants will gain a solid foundation in front-end development and be able to build responsive websites that are accessible across various devices. Front End Web Development Training for Everyone Course Curriculum Section 01: Complete Front-End Development Journey Section 02: Cascading style sheets Section 03: Transitions and Data Types Section 04: Advanced JavaScript and Its Features Section 05: JQuery and Selectors Section 06: Bootstrap and Grid System Section 07: Creating Portfolio Page How is the course assessed? Upon completing an online module, you will immediately be given access to a specifically crafted MCQ test. For each test, the pass mark will be set to 60%. Exam & Retakes: It is to inform our learners that the initial exam for this online course is provided at no additional cost. In the event of needing a retake, a nominal fee of £9.99 will be applicable. Certification Upon successful completion of the assessment procedure, learners can obtain their certification by placing an order and remitting a fee of __ GBP. £9 for PDF Certificate and £15 for the Hardcopy Certificate within the UK ( An additional £10 postal charge will be applicable for international delivery). CPD 10 CPD hours / points Accredited by CPD Quality Standards Who is this course for? Individuals who want to learn the basics of front-end web development and enhance their knowledge and skills Professionals who are looking to switch their careers to front-end web development Business owners who want to develop their own website or manage their existing website Freelancers who want to offer front-end web development services to their clients Students who want to learn front-end web development as a part of their curriculum or as a hobby. Requirements There are no formal entry requirements for the course, with enrollment open to anyone! Career path Front-end Developer: £20,000 - £60,000 UI/UX Designer: £22,000 - £70,000 Web Designer: £18,000 - £50,000 Web Developer: £22,000 - £70,000 Full Stack Developer: £30,000 - £90,000 Certificates Certificate of completion Digital certificate - £9 You can apply for a CPD Accredited PDF Certificate at the cost of £9. Certificate of completion Hard copy certificate - £15 Hard copy can be sent to you via post at the expense of £15.
Building websites isn't just for tech wizards in dark rooms with twelve monitors and too much coffee. This course opens the door to front end web development with a clear, approachable focus on HTML, CSS, and JavaScript — the trio responsible for everything from buttons that behave to layouts that don’t fall apart. Whether you're curious about code or just tired of wondering how websites actually work, this course offers a straightforward guide without the confusing lingo. Delivered entirely online, the content is designed to help you understand how modern web pages are built and how elements fit together across devices and browsers. You'll explore structure, styling, and interactivity in bite-sized lessons that get to the point without dressing it up in unnecessary fluff. It’s front end training made for everyone — with no dramatic sales pitch, just the solid basics, explained clearly, with a healthy dose of digital common sense. â±â± Front End Web Development Training for Everyone Course Curriculum Section 01: Complete Front-End Development Journey Section 02: Cascading style sheets Section 03: Transitions and Data Types Section 04: Advanced JavaScript and Its Features Section 05: JQuery and Selectors Section 06: Bootstrap and Grid System Section 07: Creating Portfolio Page How is the course assessed? Upon completing an online module, you will immediately be given access to a specifically crafted MCQ test. For each test, the pass mark will be set to 60%. Exam & Retakes: It is to inform our learners that the initial exam for this online course is provided at no additional cost. In the event of needing a retake, a nominal fee of £9.99 will be applicable. Certification Upon successful completion of the assessment procedure, learners can obtain their certification by placing an order and remitting a fee of £9 for PDF Certificate and £15 for the Hardcopy Certificate within the UK ( An additional £10 postal charge will be applicable for international delivery). CPD 10 CPD hours / points Accredited by CPD Quality Standards Who is this course for? Individuals who want to learn the basics of front-end web development and enhance their knowledge and skills Professionals who are looking to switch their careers to front-end web development Business owners who want to develop their own website or manage their existing website Freelancers who want to offer front-end web development services to their clients Students who want to learn front-end web development as a part of their curriculum or as a hobby. Requirements There are no formal entry requirements for the course, with enrollment open to anyone! Career path Front-end Developer: £20,000 - £60,000 UI/UX Designer: £22,000 - £70,000 Web Designer: £18,000 - £50,000 Web Developer: £22,000 - £70,000 Full Stack Developer: £30,000 - £90,000 Certificates Certificate of completion Digital certificate - £9 You can apply for a CPD Accredited PDF Certificate at the cost of £9. Certificate of completion Hard copy certificate - £15 Hard copy can be sent to you via post at the expense of £15.
Demystify the power of graphs and unlock their potential with our Graph Theory Algorithms Course. Master fundamental algorithms like Depth-First Search and Breadth-First Search, explore pathfinding techniques, and delve into advanced graph concepts. Enrol now to sharpen your skills and become proficient in graph theory.