You can typically use most of the SAS programming statements and SAS functions that you can use in a DATA step for defining the FCMP functions and subroutines. However, there are a few differences in the capabilities of the DATA step and the FCMP procedure. For more information, see the "FCMP Procedure" chapter in the Base SAS Procedures Guide.
All variables listed in the ID and VAR statements are assigned as predefined arrays for subsequent processing. Additionally, all of the array names listed in the OUTARRAYS statements and all of the scalars names listed in the OUTSCALARS statements are assigned as predefined symbols for subsequent processing.