Module function 

User-defined functions (FUNCTION-ID): the rules a definition or prototype keeps, the prototypes an invocation is checked against (Language Reference, the USING phrase’s conformance of parameters for user-defined functions), and the formal parameters and result the interpreter invokes one with.

Structs

Formal

A formal parameter or the RETURNING item: what an argument conforms to, and the shape of the temporary that holds a literal or expression argument.

Udf

A user-defined function as an invocation sees it.

Functions

check_invocation

The invocation of udf at f: its argument count, and each data-item argument against its formal parameter.

conformance

Why argument item of the caller’s layout does not conform to formal. A literal or an expression has no description to conform: it is moved or computed into a temporary of the formal parameter’s (assumption C272).

functions

The functions a program may invoke, each laid out once. A prototype that does not lay out is left out here: compiling it reports why, and an invocation of it is then unknown. One named as an intrinsic function is left out unless the REPOSITORY paragraph names it, as the name then invokes the intrinsic function (assumption C271).

signature

The function as its prototype’s LINKAGE SECTION and PROCEDURE DIVISION header describe it.