subtract package:ghc-typelits-natnormalise

Subtract an inequality, in order to either:
  • See if the smallest solution is a natural number
  • Cancel sums, i.e. monotonicity of addition
subtractIneq (2*y <=? 3*x ~ True)  = 3*x + (-2)*y
subtractIneq (2*y <=? 3*x ~ False) = -3*x + (-2)*y