HP-48SX MOD issue

[Rick314]

I was transferring a program from the HP-28S to the HP-48SX and found the following issue. On the HP-28S 'MOD(5,2)' ->NUM results in the expected answer of 1. On the HP-48SX 'MOD(5,2)' can't be entered. It appears the HP-48SX won't allow MOD to appear in an algebraic expression. Others like 'MAX(5,2)' EVAL or 'PERM(5,2)' EVAL work as expected on the HP-48SX. I read about MOD in the HP-48 Programmer's Reference Manual and found nothing related there. Is this a defect or am I misunderstanding something?