IV.4 Semantics of Expressions

Semantics of expressions [Slide 121]

Let E⟦…⟧(…) be the “meaning” (semantic) function from Expressions × Σ to Val (integer or Boolean values) and let σ0 be a state then

E⟦z⟧(σ0)
=
z
E⟦A⟧(σ0)
=
σ0(A)
E⟦ig(ie1,…,ien)⟧(σ0)
=
ig(E⟦ie1⟧(σ0),…,E⟦ien⟧(σ0))
E⟦b⟧(σ0)
=
b
E⟦Q⟧(σ0)
=
σ0(Q)
E⟦bg(be1,…,ben)⟧(σ0)
=
bg(E⟦be1⟧(σ0),…,E⟦ben⟧(σ0))

Example 32.  

E⟦Account⟧(σ0)
=
σ0(Account)
   
E⟦In⟧(σ0)
=
σ0(In)
   
E⟦Account + In⟧(σ0)
=
E⟦Account⟧(σ0)+E⟦In⟧(σ0)
=
σ0(Account)+σ0(In)

2024-08-02
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