How can you have two equal signs in that statement? Mathematically or Logically it doesn't make sense, and the compiler is telling you it doesn't like it. It is however trying to Parse that line and attempting to call a routine to handle that expression... but there isn't one. When mathematicians figure out a way of handling that, you are safe in the knowledge that your PICBasic compiler already has the internal hooks to slot-in a routine for it...

After you correct that, you'll also discover you've a ; (Assembler comment marker) when you should have had a ' (the PICBasic comment marker)... but a lot of people don't know that PICBasic will accept that... so you've discovered one of those undocumented features...