... Principles of Programming Languages, 1Undergraduate Topics in Computer Science, DOI 10.1007/978-1-84882-032-6_1,c Springer-Verlag London Limited 20091.1 Five ConstructsMost programming languages ... fact that there does not exist a surjective function of N inthe set of functions from N to N.2FunctionsG. Dowek, Principles of Programming Languages, 19Undergraduate Topics in Computer Science, ... circular, since to define the value of an expression of the form t+u, we use the value of expressions t and u.But the size of these expressions is smaller than that of t+u. This definitionis therefore...