1 files changed, 5 insertions, 11 deletions
diff --git a/differentiator.cpp b/differentiator.cpp
index d25366d..5f8fffa 100644
--- a/differentiator.cpp
+++ b/differentiator.cpp
@@ -75,17 +75,11 @@ Expression *Differentiator::visit(SubExpression *expr) const {
 // Regla de la potencia. f(x)=x^c, f'(x)=c*x^(c-1)}*f'(x).
 Expression *Differentiator::visit(PowerExpression *expr) const {
   Literal *c = dynamic_cast<Literal *>(expr->getRight());
-  Variable *x = dynamic_cast<Variable *>(expr->getLeft());
-  
-  /* Si el valor izquierdo no es un número, entonces el derecho
-     lo es. */
-  if(c == NULL) {
-    c = dynamic_cast<Literal *>(expr->getLeft());
-    x = dynamic_cast<Variable *>(expr->getRight());
-  }
-  
-  return new MultiplicationExpression(new MultiplicationExpression(c->copy(), new PowerExpression(x->copy(), new Literal(c->getValue() - 1))),
-				      expr->getLeft()->diff(this));
+  Expression *left = expr->getLeft();
+
+  return new MultiplicationExpression(new MultiplicationExpression
+				      (new Literal(c->getValue()), new PowerExpression(left->copy(), new Literal(c->getValue() - 1))),
+				      left->diff(this));
 }
 
 // Regla del producto.