Pensieve Header: A very simple - minded permutation calculator for MAT1100.

Unprotect[And];
p1_Integer && p2_Integer := Module[
{s1, s2},
s1 = IntegerDigits[Abs[p1]];
If[p1<0, s1 = Ordering[s1]];
s2 = IntegerDigits[Abs[p2]];
If[p2<0, s2 = Ordering[s2]];
FromDigits[s1[[s2]]]
];
Protect[And];

s1=2314; s2=2143;

s12=s1

s13=s12&&s12

s13&&s12

s12&&s13

s13&&s13

-s12&&2314

-s12&&s2

-4132&&4123