As the definition of “lt” is “not(geq)” lt will succeed for every term where “geq” fails.
Unfortunately this also include comparison of couple that are not necessary integer/real couples.

(Foo(), Bar()) succeeds

Submitted on 11 August 2008 at 11:17

STR-757, karltk:
I’m not entirely certain this is a bug or not.

We use fail/succeed to signal whether t1 is less than t2 ( (t1, t2)). For (Foo(), Bar()), it’s just not defined. Success and failure are both equally wrong if you expect lt to compare numbers.

If you change lt to fail for non-numbers, the code using lt erroneously like you show, would in all likelihood assume that t1 is geq than t2 when lt fails. I don’t see that this is any better.

We should really throw an exception, but we don’t have any in Stratego.