Summary: [For the entire collection see Zbl 0713.00018.]
\(\lambda\)-calculus is considered a useful mathematical tool in the study of programming languages. However, if one uses \(\beta\eta\)-conversion to prove equivalence of programs, then a considerable simplification is introduced. We give a calculus based on a categorical semantics for computations, which provides a correct basis for proving equivalence of programs, independent of any specific computational model.