What is the standard definition of valuation of propositions in an Heyting algebra?
A valuation of propositions of a propositional language in an Heyting algebra $(H, \wedge, \vee, \rightarrow, 1, 0)$ should be a mapping $V:PROP \to H$ such that $V(\bot)=0$, $V(\top)=1$, $V(A \wedge B)=V(A) \wedge V(B)$, $V(A \vee B)=V(A) \vee V(B)$ and $V(A \rightarrow B)=V(A) \rightarrow V(B)$.
Can you confirm that this is the standard definition, eventually posting some references?