axExpDef = mkBinAxiom "ExpDef" typeNatExpTyCon $
              \x y -> Just $ num (x ^ y)
axExpDef = mkBinAxiom "ExpDef" typeNatExpTyCon $
              \x y -> Just $ num (x ^ y)
axExpDef = mkBinAxiom "ExpDef" typeNatExpTyCon $
              \x y -> Just $ num (x ^ y)