Module 2.7: Dynamic Semantics

Vocabulary-style flashcards covering Dynamic Semantics, including Operational, Denotational, and Axiomatic methods as described in the lecture notes.

Dynamic Semantics

Describing the meaning of the program or of a statement.

Operational Semantics

Describes the meaning of a program by executing its statements on a machine, either simulated or actual, where the change in the state of the machine (memory, registers, etc.) defines the meaning of the statement.

High-Level Operational Semantics (Natural)

Operational semantics where the final result of program execution is of interest.

Low-Level Operational Semantics (Structural)

Operational semantics where the sequence of state changes caused by program execution is of interest.

Denotational Semantics

A semantics method based on recursive function theory, where a mathematical object is defined for each language entity and meaning is defined by symbols of the program's variables.

Axiomatic Semantics

The most abstract semantics method, based on formal logic (predicate calculus) and originally intended for formal program verification.

Scott and Strachey (1970)

Individuals who developed the process of building a denotational specification for a language.

Assertions

The name used for expressions in axiomatic semantics.

Precondition

An assertion before a statement that states the relationships and constraints among variables that are true at that point in execution.

Postcondition

An assertion following a statement.

Weakest precondition

The least restrictive precondition that will guarantee the postcondition.

Induction

Deduction

Contradiction

Counterexample

Contrapositive

The five types of proofs used to decode a program in axiomatic semantics.