# Question: How do I test a variable against itself for a value

August 22 2011 by
false

0

How do I test a variable against itself to see if it has a value or not?

As an example

p1:=sin(x)
p2:=46

[seq(if(p||i=p||i,p||i,NULL),i=1..5)]  # when p||i actually equals p||i and not some value ie sequence should not include p3,p4 and p5