bugfix: when simplifing an expression, only mask an atom if this atom could be replaced by a variable.
bugfix: when simplifing an expression, only mask an atom if this atom could be replaced by a variable.


prowessproject/wrangler,arcusfelis/wrangler,bsmr-erlang/wrangler,andrzejsliwa/wrangler,tdb/wrangler,arcusfelis/wrangler