 Definition 1.4 (Computational adequacy). A denotational semantics \({\mathcal{M}}\) is computationally adequate with respect to an operational semantics \({\mathcal{O}}\) if, for all programs \(e\) and all values \(v\)  \[{\mathcal{O}}(e) = v \ \text{ if and only if } \ {\mathcal{M}}(e) = {\mathcal{M}}(v).\]   