Fix __mro__ problem in inheritance

1 files changed, 5 insertions, 5 deletions

diff --git a/mdpoly/algebra.py b/mdpoly/algebra.py
index a9fc806..a2d2325 100644
--- a/mdpoly/algebra.py
+++ b/mdpoly/algebra.py
@@ -77,7 +77,7 @@ class ExprWithRepr(Expr, HasRepr, Protocol):
     """ Expression that has a representation """
 
 
-class ReducibleExpr(HasRepr, Protocol):
+class ReducibleExpr(ExprWithRepr, Protocol):
     """ Reducible Expression
 
     Algebraic expression that can be written in terms of other (existing)
@@ -187,7 +187,7 @@ class Add(Expr, HasRepr):
         return f"({self.left} + {self.right})"
 
 
-class Sub(Expr, ReducibleExpr):
+class Sub(ReducibleExpr):
     """ Generic subtraction operator (no type check) """
 
     @property
@@ -200,7 +200,7 @@ class Sub(Expr, ReducibleExpr):
     def reduce(self) -> ExprWithRepr:
         """ See :py:meth:`mdpoly.algebra.ReducibleExpr.reduce`. """
         # return self.left + (-1 * self.right)
-        return Add(self.left, Mul(self._constant(value=-1), self.right))
+        return Add(self.left, Mul(Const(value=-1), self.right))
 
     def __repr__(self) -> str:
         return f"({self.left} - {self.right})"
@@ -242,7 +242,7 @@ class Mul(Expr, HasRepr):
         return f"({self.left} * {self.right})"
 
 
-class Exp(Expr, ReducibleExpr):
+class Exp(ReducibleExpr):
     """ Generic exponentiation (no type check). """
 
     @property
@@ -334,7 +334,7 @@ class PolyMul(Mul, PolyRingAlgebra):
 
 
 @binary_operator(PolyRingAlgebra, PolyRingAlgebra)
-class PolyDiv(Expr, ReducibleExpr, PolyRingAlgebra):
+class PolyDiv(ReducibleExpr, PolyRingAlgebra):
     """ Division of scalar polynomial by scalar. """
 
     def reduce(self) -> ExprWithRepr: