PERM INDEX

PERM _ _ _ _ _ _ _ _ _ _ _ _ operator

syntax:

perm(<expression1>,<expression2>)

If <expression1> and <expression2> evaluate to positive integers, perm returns the number of permutations possible in selecting <expression1> objects from <expression2> objects. In other cases, an expression in the original operator is returned.

examples:


perm(1,1); 

  1 


perm(3,5); 

  60 


perm(-3,5); 

  PERM(-3,5) 


perm(a,b); 

  PERM(A,B)