diff --git a/kalk/src/analysis.rs b/kalk/src/analysis.rs
index 46d128b..1697fc4 100644
--- a/kalk/src/analysis.rs
+++ b/kalk/src/analysis.rs
@@ -207,12 +207,21 @@ fn analyse_binary<'a>(
             // Equation
             context.in_equation = true;
             let left = analyse_expr(context, left)?;
+
+            // If it has already been set to false manually somewhere else,
+            // abort and analyse as a comparison instead.
+            if context.in_equation == false {
+                context.in_conditional = true;
+                return analyse_binary(context, left, op, right);
+            }
+
             context.in_equation = false;
 
             let var_name = if let Some(var_name) = &context.equation_variable {
                 var_name
             } else {
-                return Err(CalcError::UnableToSolveEquation);
+                context.in_conditional = true;
+                return analyse_binary(context, left, op, right);
             };
 
             let inverted = if inverter::contains_var(&mut context.symbol_table, &left, var_name) {
@@ -231,6 +240,7 @@ fn analyse_binary<'a>(
                 Identifier::from_full_name(var_name),
                 Box::new(inverted.clone()),
             ));
+            context.equation_variable = None;
 
             return Ok(inverted);
         }
@@ -378,6 +388,11 @@ fn build_fn_call(
         context.in_integral = true;
     }
 
+    // Don't perform equation solving on special functions
+    if is_integral || identifier.full_name == "sum" || identifier.full_name == "prod" {
+        context.in_equation = false;
+    }
+
     let arguments = match adjacent_expr {
         Expr::Vector(arguments) => {
             let mut new_arguments = Vec::new();
@@ -484,7 +499,7 @@ fn build_split_up_vars(
     Ok(left)
 }
 
-fn build_var(context: &Context, name: &str) -> Expr {
+fn build_var(context: &mut Context, name: &str) -> Expr {
     if let (Some(function_name), Some(params)) = (
         context.current_function_name.as_ref(),
         context.current_function_parameters.as_ref(),
@@ -494,5 +509,10 @@ fn build_var(context: &Context, name: &str) -> Expr {
             return Expr::Var(identifier);
         }
     }
-    return Expr::Var(Identifier::from_full_name(name));
+
+    if context.in_equation && !context.symbol_table.contains_var(name) {
+        context.equation_variable = Some(name.to_string());
+    }
+
+    Expr::Var(Identifier::from_full_name(name))
 }