1 files changed, 39 insertions, 2 deletions
diff --git a/expressions.cpp b/expressions.cpp
index 72e1e04..6046a9c 100644
--- a/expressions.cpp
+++ b/expressions.cpp
@@ -4,6 +4,7 @@
 #include "include/lexer.hpp"
 #include "include/expressions.hpp"
 #include "include/differentiator.hpp"
+#include "include/simplifier.hpp"
 
 using std::string, std::to_string;
 
@@ -30,6 +31,10 @@ Expression *Literal::diff(const Differentiator *d) {
   return d->visit(this);
 }
 
+Expression *Literal::simplify(const Simplifier *s) {
+  return s->visit(this);
+}
+
 Expression *Literal::copy() {
   return new Literal(value);
 }
@@ -56,6 +61,10 @@ Expression *Function::diff(const Differentiator *d) {
   return d->visit(this);
 }
 
+Expression *Function::simplify(const Simplifier *s) {
+  return s->visit(this);
+}
+
 void Function::delTree() {
   delete arg;
 }
@@ -136,6 +145,10 @@ Expression *Variable::diff(const Differentiator *d) {
   return d->visit(this);
 }
 
+Expression *Variable::simplify(const Simplifier *s) {
+  return s->visit(this);
+}
+
 Expression *Variable::copy() {
   return new Variable(name);
 }
@@ -159,6 +172,10 @@ Expression *AddExpression::diff(const Differentiator *d) {
   return d->visit(this);
 }
 
+Expression *AddExpression::simplify(const Simplifier *s) {
+  return s->visit(this);
+}
+
 Expression *AddExpression::copy() {
   return new AddExpression(left->copy(), right->copy());
 }
@@ -172,16 +189,20 @@ SubExpression::~SubExpression() {
 }
 
 float SubExpression::eval(int arg) {
-  float right_val = right->eval(arg);
   float left_val = left->eval(arg);
+  float right_val = right->eval(arg);
 
-  return right_val - left_val;
+  return left_val - right_val;
 }
 
 Expression *SubExpression::diff(const Differentiator *d) {
   return d->visit(this);
 }
 
+Expression *SubExpression::simplify(const Simplifier *s) {
+  return s->visit(this);
+}
+
 Expression *SubExpression::copy() {
   return new SubExpression(left->copy(), right->copy());
 }
@@ -209,6 +230,10 @@ Expression *NegationExpression::diff(const Differentiator *d) {
   return d->visit(this);
 }
 
+Expression *NegationExpression::simplify(const Simplifier *s) {
+  return s->visit(this);
+}
+
 Expression *NegationExpression::copy() {
   return new NegationExpression(right->copy());
 }
@@ -232,6 +257,10 @@ Expression *DivisionExpression::diff(const Differentiator *d) {
   return d->visit(this);
 }
 
+Expression *DivisionExpression::simplify(const Simplifier *s) {
+  return s->visit(this);
+}
+
 Expression *DivisionExpression::copy() {
   return new DivisionExpression(left->copy(), right->copy());
 }
@@ -256,6 +285,10 @@ Expression *MultiplicationExpression::diff(const Differentiator *d) {
   return d->visit(this);
 }
 
+Expression *MultiplicationExpression::simplify(const Simplifier *s) {
+  return s->visit(this);
+}
+
 Expression *MultiplicationExpression::copy() {
   return new MultiplicationExpression(left->copy(), right->copy());
 }
@@ -279,6 +312,10 @@ Expression *PowerExpression::diff(const Differentiator *d) {
   return d->visit(this);
 }
 
+Expression *PowerExpression::simplify(const Simplifier *s) {
+  return s->visit(this);
+}
+
 Expression *PowerExpression::copy() {
   return new PowerExpression(left->copy(), right->copy());
 }