(* the type cexpr is inspired by OpenMath. A few primitive constructors
have been added, in order to take into account some special features
of functional expressions. Most notably: case, let in, let rec, and
(* the type cexpr is inspired by OpenMath. A few primitive constructors
have been added, in order to take into account some special features
of functional expressions. Most notably: case, let in, let rec, and