Logical operators used in custom cards

I’m trying to tweak a custom state card written by another user but I can’t find any information on a couple of things i’m stuck on:

  1. Does anyone know how the syntax to use logical operators to set the state of a boolean in the code? I’ve tried “_boolean3: (_boolean1) && (_boolean2)” which gives errors. I tried it without the (). I’ve tried with {}. I’ve tried with {()}. etc…

  2. what is the way to set the background color of a paper-button dynamically with the state of a boolean? I have the background default style but I want to change the background style based on the state of a boolean defined in the code.

I’ve done searches for every iteration of those search terms I can think of and can’t find the answers. Everything I’ve found has been very basic or unrelated to the questions I have. Comprehensive Polymer documentation is pretty hard to find. If anybody knows a good comprehensive primer that would awesome to know.