Objects defined by subtypes derived from a base type are considered being of the same type
Example:
PROCESS
SUBTYPE smallintA IS integer (RANGE 0 to 10);
SUBTYPE smallintB IS integer (RANGE 0 to 15);
VARIABLE A: smallintA := 5;
VARIABLE B: smallintB := 8;
VARIABLE C: integer;
BEGIN
B := B * A; --OK
C := B + 1; --OK
END PROCESS;
