const pi : double = "M_PI"; const M_PI : double; const myval[t] : int = "(?1)(x+y)";When the target and source names are the same, the source string can be elided.
When used in an expression, the Felix symbol is replaced by the correspondong C code, with substitution of type variables if necessary.
The const declaration is a short form for a function with no arguments. Const definitions can also have requirements clauses. See requirements for more details.