What is formal specification ? Discuss interface specification in detail.

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Formal Specification

 - Formal specification is a part of a more general collection of techniques that are known as the "formal method".

Example:- COMP313"Formal methods" (These are all based on the mathematical representation and analysis of software.)

- Formal methods include :

  • Formal specification
  • Specification analysis and proof 
  • Transformation development
  • Program verification

Interface Specification
- Large systems are decomposed into subsystems with well-defined interfaces between these subsystems.
- Specification of subsystem interfaces allows independent development of the different subsystems.
- Interfaces may be defined as abstract data types or object classes.
- The algebraic approach to formal specification is particularly well-suited to the interface specification
- Most systems must operate with existing systems and operating interfaces must be precisely specified as part of the required.

Types of Interface Specification
a) Procedural Interfaces
- Used for calling the existing programs

b) Data structures
-Provides data passing from one subsystem to another 

c) Representation of data
- Ordering of bits to match with an existing system.
- Formal notations are effective techniques for interface specification but their specialized nature means they are difficult to understand without special training.

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