T()(A) I( A(o)=I(A)(o)if A is a wff I(AVBo)=I(A(oVI(B)(o)if A and B are wtrs If a is a wff and x is an individual variable if there exists d∈D such that I(A)(olc/d t otherwise Logic in Computer Science -p 7/18I(σ)(A) • I(∼ A)(σ) = ¬I(A)(σ) if A is a wff. • I(A ∨ B)(σ) = I(A)(σ)∨I(B)(σ) if A and B are wffs. • If A is a wff and x is an individual variable, I(∀xA)(σ) =  F if there exists d ∈ D such that I(A)(σ[x/d]) = F T otherwise Logic in Computer Science – p.7/18