diff --git a/http/simplify.http b/http/simplify.http
index 32c5f91..74bdae7 100644
--- a/http/simplify.http
+++ b/http/simplify.http
@@ -123,3 +123,18 @@ GET {{url}}/simplify/{{expression}}
 ### GET with simplify="true"
 
 GET {{url}}/simplify/A?simplify=true&hide=NONE&sort=DEFAULT&caseSensitive=false&hideIntermediate=false
+
+### GET and ignore case
+
+< {%
+    import {expression} from "./common";
+
+    expression("A & a")
+%}
+GET {{url}}/simplify/{{expression}}?ignoreCase=true
+
+> {%
+    client.test("Response body is the same as the input", () => {
+        client.assert(response.body.after === "A", "Response body is not simplified to 'a'");
+    });
+%}
diff --git a/src/expressions/expression.rs b/src/expressions/expression.rs
index 1c9209c..63692f8 100644
--- a/src/expressions/expression.rs
+++ b/src/expressions/expression.rs
@@ -7,10 +7,6 @@ use serde::{Deserialize, Serialize};
 use crate::expressions::operator::BinaryOperator;
 use crate::parsing::expression_parser::parse_expression;
 
-pub trait OppositeEq {
-    fn opposite_eq(&self, other: &Self) -> bool;
-}
-
 #[derive(Debug, Clone, PartialEq, Eq, Hash, Deserialize, Serialize)]
 #[serde(rename_all = "camelCase")]
 pub enum Expression {
@@ -39,14 +35,32 @@ impl Expression {
             Expression::Atomic(value) => HashSet::from([value.clone()])
         }
     }
-}
 
-impl OppositeEq for Expression {
-    fn opposite_eq(&self, other: &Self) -> bool {
+    pub fn eq(&self, other: &Self, ignore_case: bool) -> bool {
+        match (self, other) {
+            (Expression::Not(left), Expression::Not(right)) => Expression::eq(left, right, ignore_case),
+            (Expression::Binary { left: left_left, operator: left_operator, right: left_right },
+                Expression::Binary { left: right_left, operator: right_operator, right: right_right }) => {
+                Expression::eq(left_left, right_left, ignore_case)
+                    && left_operator == right_operator
+                    && Expression::eq(left_right, right_right, ignore_case)
+            }
+            (Expression::Atomic(left), Expression::Atomic(right)) => {
+                if ignore_case {
+                    left.eq_ignore_ascii_case(right)
+                } else {
+                    left == right
+                }
+            }
+            _ => false
+        }
+    }
+
+    pub fn opposite_eq(&self, other: &Self, ignore_case: bool) -> bool {
         match (self, other) {
             (Expression::Not(_), Expression::Not(_)) => false,
-            (Expression::Not(left), right) => left.as_ref() == right,
-            (left, Expression::Not(right)) => left == right.as_ref(),
+            (Expression::Not(left), right) => left.as_ref().eq(right, ignore_case),
+            (left, Expression::Not(right)) => left.eq(right.as_ref(), ignore_case),
             _ => false,
         }
     }
@@ -99,6 +113,48 @@ mod tests {
     use crate::expressions::expression::Expression;
     use crate::expressions::helpers::{and, atomic, implies, not, or};
 
+    #[test]
+    fn test_eq_ignore_case_atomics() {
+        let expression_lower = atomic("a");
+        let expression_upper = atomic("A");
+        assert!(expression_lower.eq(&expression_upper, true));
+    }
+
+    #[test]
+    fn test_eq_ignore_case_not() {
+        let expression_lower = not(atomic("a"));
+        let expression_upper = not(atomic("A"));
+        assert!(expression_lower.eq(&expression_upper, true));
+    }
+
+    #[test]
+    fn test_eq_ignore_case_and() {
+        let expression_lower = and(atomic("a"), atomic("b"));
+        let expression_upper = and(atomic("A"), atomic("B"));
+        assert!(expression_lower.eq(&expression_upper, true));
+    }
+
+    #[test]
+    fn test_eq_ignore_case_equal() {
+        let expression_lower = or(atomic("a"), atomic("b"));
+        let expression_upper = or(atomic("a"), atomic("b"));
+        assert!(expression_lower.eq(&expression_upper, true));
+    }
+
+    #[test]
+    fn test_eq_ignore_case_unequal() {
+        let expression_lower = or(atomic("a"), atomic("b"));
+        let expression_upper = or(atomic("a"), atomic("c"));
+        assert!(!expression_lower.eq(&expression_upper, true));
+    }
+
+    #[test]
+    fn test_eq_dont_ignore_case() {
+        let expression_lower = or(atomic("a"), atomic("b"));
+        let expression_upper = or(atomic("a"), atomic("B"));
+        assert!(!expression_lower.eq(&expression_upper, false));
+    }
+
     #[test]
     fn test_expression_a_and_not_b_display() {
         let expression = and(
diff --git a/src/expressions/simplify.rs b/src/expressions/simplify.rs
index 7cd18ab..7420161 100644
--- a/src/expressions/simplify.rs
+++ b/src/expressions/simplify.rs
@@ -2,9 +2,10 @@ use std::ops::Deref;
 
 use serde::Serialize;
 
-use crate::expressions::expression::{Expression, OppositeEq};
+use crate::expressions::expression::Expression;
 use crate::expressions::helpers::{and, binary, not, or};
 use crate::expressions::operator::BinaryOperator;
+use crate::routing::options::SimplifyOptions;
 use crate::routing::response::Operation;
 
 #[derive(Debug, PartialEq, Serialize)]
@@ -21,19 +22,19 @@ pub enum Law {
 
 #[macro_export]
 macro_rules! absorption_law_opposites {
-    ($left:expr, $right:expr, $operations:expr, $op:pat, $func:expr) => {
+    ($left:expr, $right:expr, $operations:expr, $op:pat, $func:expr, $ignore_case:expr) => {
         match ($left.as_ref(), $right.as_ref()) {
             (_, Expression::Binary { left: right_left, operator: $op, right: right_right }) => {
-                evaluate_equals_or_opposites($left.as_ref(), right_left, right_right, $func, $operations).unwrap_or(
-                    $func($left.absorption_law($operations), $right.absorption_law($operations))
+                evaluate_equals_or_opposites($left.as_ref(), right_left, right_right, $func, $ignore_case, $operations).unwrap_or(
+                    $func($left.absorption_law($operations, $ignore_case), $right.absorption_law($operations, $ignore_case))
                 )
             }
             (Expression::Binary { left: left_left, operator: $op, right: left_right }, _) => {
-                evaluate_equals_or_opposites($right.as_ref(), left_left, left_right, $func, $operations).unwrap_or(
-                    $func($left.absorption_law($operations), $right.absorption_law($operations))
+                evaluate_equals_or_opposites($right.as_ref(), left_left, left_right, $func, $ignore_case, $operations).unwrap_or(
+                    $func($left.absorption_law($operations, $ignore_case), $right.absorption_law($operations, $ignore_case))
                 )
             }
-            (left, right) => $func(left.absorption_law($operations), right.absorption_law($operations))
+            (left, right) => $func(left.absorption_law($operations, $ignore_case), right.absorption_law($operations, $ignore_case))
         }
     };
 }
@@ -57,14 +58,24 @@ macro_rules! distribution_law_atomic_vs_binary {
     };
 }
 
-// TODO deduplicate code
+#[derive(Debug, Default)]
+pub struct Options {
+    pub ignore_case: bool,
+}
+
+impl From<SimplifyOptions> for Options {
+    fn from(options: SimplifyOptions) -> Self {
+        Self { ignore_case: options.ignore_case }
+    }
+}
+
 impl Expression {
     // TODO better track of operations
-    pub fn simplify(&self) -> (Self, Vec<Operation>) {
+    pub fn simplify(&self, options: Options) -> (Self, Vec<Operation>) {
         let mut operations: Vec<Operation> = vec![];
         let expression = self.elimination_of_implication(&mut operations)
             .de_morgans_laws(&mut operations)
-            .absorption_law(&mut operations)
+            .absorption_law(&mut operations, options.ignore_case)
             // .associative_law(&mut operations)
             .distribution_law(&mut operations)
             .double_negation_elimination(&mut operations);
@@ -149,23 +160,24 @@ impl Expression {
         result
     }
 
-    fn absorption_law(&self, operations: &mut Vec<Operation>) -> Self {
+    fn absorption_law(&self, operations: &mut Vec<Operation>, ignore_case: bool) -> Self {
         let result = match self {
-            Expression::Binary { left, operator: BinaryOperator::And | BinaryOperator::Or, right } if left == right => {
-                left.absorption_law(operations)
+            Expression::Binary { left, operator: BinaryOperator::And | BinaryOperator::Or, right }
+            if Expression::eq(left, right, ignore_case) => {
+                left.absorption_law(operations, ignore_case)
             }
             Expression::Binary { left, operator: BinaryOperator::And, right } => {
-                absorption_law_opposites!(left, right, operations, BinaryOperator::Or, and)
+                absorption_law_opposites!(left, right, operations, BinaryOperator::Or, and, ignore_case)
             }
             Expression::Binary { left, operator: BinaryOperator::Or, right } => {
-                absorption_law_opposites!(left, right, operations, BinaryOperator::And, or)
+                absorption_law_opposites!(left, right, operations, BinaryOperator::And, or, ignore_case)
             }
             Expression::Binary { left, operator, right } => binary(
-                left.absorption_law(operations),
+                left.absorption_law(operations, ignore_case),
                 *operator,
-                right.absorption_law(operations),
+                right.absorption_law(operations, ignore_case),
             ),
-            Expression::Not(expr) => not(expr.absorption_law(operations)),
+            Expression::Not(expr) => not(expr.absorption_law(operations, ignore_case)),
             atomic => atomic.clone(),
         };
         if let Some(operation) = Operation::new(self, &result, Law::AbsorptionLaw) {
@@ -210,15 +222,16 @@ fn evaluate_equals_or_opposites<F: Fn(Expression, Expression) -> Expression>(
     left: &Expression,
     right: &Expression,
     ret_func: F,
+    ignore_case: bool,
     operations: &mut Vec<Operation>,
 ) -> Option<Expression> {
-    if this == left || this == right {
-        return Some(this.absorption_law(operations));
-    } else if left.is_atomic() && right.is_atomic() && this.opposite_eq(left) {
-        if this.opposite_eq(left) {
-            return Some(ret_func(right.absorption_law(operations), this.absorption_law(operations)));
-        } else if this.opposite_eq(right) {
-            return Some(ret_func(left.absorption_law(operations), this.absorption_law(operations)));
+    if this.eq(left, ignore_case) || this.eq(right, ignore_case) {
+        return Some(this.absorption_law(operations, ignore_case));
+    } else if left.is_atomic() && right.is_atomic() && this.opposite_eq(left, ignore_case) {
+        if this.opposite_eq(left, ignore_case) {
+            return Some(ret_func(right.absorption_law(operations, ignore_case), this.absorption_law(operations, ignore_case)));
+        } else if this.opposite_eq(right, ignore_case) {
+            return Some(ret_func(left.absorption_law(operations, ignore_case), this.absorption_law(operations, ignore_case)));
         }
     }
     None
@@ -231,7 +244,7 @@ mod tests {
 
     #[test]
     fn test_simplify() {
-        let (expression, operations) = implies(atomic("a"), atomic("b")).simplify();
+        let (expression, operations) = implies(atomic("a"), atomic("b")).simplify(Default::default());
         assert_eq!(expression, or(not(atomic("a")), atomic("b")));
         assert_eq!(operations.len(), 1);
         assert_eq!(operations[0].law, Law::EliminationOfImplication);
@@ -239,7 +252,7 @@ mod tests {
 
     #[test]
     fn test_simplify_a_and_a() {
-        let (expression, operations) = and(atomic("a"), atomic("a")).simplify();
+        let (expression, operations) = and(atomic("a"), atomic("a")).simplify(Default::default());
         assert_eq!(expression, atomic("a"));
         assert_eq!(operations.len(), 1);
         assert_eq!(operations[0].law, Law::AbsorptionLaw);
@@ -247,7 +260,7 @@ mod tests {
 
     #[test]
     fn test_implication_and_de_morgans() {
-        let expression = implies(and(not(atomic("a")), atomic("b")), atomic("c")).simplify().0;
+        let expression = implies(and(not(atomic("a")), atomic("b")), atomic("c")).simplify(Default::default()).0;
         assert_eq!(expression, or(or(atomic("a"), not(atomic("b"))), atomic("c")));
     }
 
@@ -390,21 +403,21 @@ mod tests {
     #[test]
     fn test_absorption_law_and() {
         let mut operations = vec![];
-        let expression = and(atomic("a"), or(atomic("a"), atomic("b"))).absorption_law(&mut operations);
+        let expression = and(atomic("a"), or(atomic("a"), atomic("b"))).absorption_law(&mut operations, false);
         assert_eq!(expression, atomic("a"));
     }
 
     #[test]
     fn test_absorption_law_or() {
         let mut operations = vec![];
-        let expression = or(atomic("a"), and(atomic("a"), atomic("b"))).absorption_law(&mut operations);
+        let expression = or(atomic("a"), and(atomic("a"), atomic("b"))).absorption_law(&mut operations, false);
         assert_eq!(expression, atomic("a"));
     }
 
     #[test]
     fn test_absorption_law_nested_and() {
         let mut operations = vec![];
-        let expression = and(atomic("a"), or(atomic("a"), atomic("b"))).absorption_law(&mut operations);
+        let expression = and(atomic("a"), or(atomic("a"), atomic("b"))).absorption_law(&mut operations, Default::default());
         assert_eq!(expression, atomic("a"));
     }
 
@@ -412,7 +425,7 @@ mod tests {
     #[test]
     fn test_absorption_law_not() {
         let mut operations = vec![];
-        let expression = or(and(not(atomic("a")), atomic("b")), atomic("a")).absorption_law(&mut operations);
+        let expression = or(and(not(atomic("a")), atomic("b")), atomic("a")).absorption_law(&mut operations, Default::default());
         assert_eq!(expression, or(atomic("b"), atomic("a")));
     }
 
@@ -420,7 +433,7 @@ mod tests {
     #[test]
     fn test_absorption_law_not_reversed() {
         let mut operations = vec![];
-        let expression = or(and(atomic("a"), atomic("b")), not(atomic("a"))).absorption_law(&mut operations);
+        let expression = or(and(atomic("a"), atomic("b")), not(atomic("a"))).absorption_law(&mut operations, Default::default());
         assert_eq!(expression, or(atomic("b"), not(atomic("a"))));
     }
 
@@ -428,7 +441,7 @@ mod tests {
     #[test]
     fn test_absorption_law_double_not() {
         let mut operations = vec![];
-        let expression = or(and(not(atomic("a")), atomic("b")), not(atomic("a"))).absorption_law(&mut operations);
+        let expression = or(and(not(atomic("a")), atomic("b")), not(atomic("a"))).absorption_law(&mut operations, Default::default());
         assert_eq!(expression, not(atomic("a")));
     }
 
@@ -436,7 +449,7 @@ mod tests {
     fn test_absorption_law_duplicate_atomic() {
         let mut operations = vec![];
         let expression = and(atomic("A"), atomic("A"));
-        let simplified = expression.absorption_law(&mut operations);
+        let simplified = expression.absorption_law(&mut operations, Default::default());
         assert_eq!(simplified, atomic("A"));
         assert_eq!(operations.len(), 1);
         assert_eq!(operations[0].law, Law::AbsorptionLaw);
@@ -448,7 +461,7 @@ mod tests {
     #[test]
     fn test_in_parenthesis() {
         let mut operations = vec![];
-        let expression = and(or(atomic("a"), atomic("b")), not(atomic("a"))).absorption_law(&mut operations);
+        let expression = and(or(atomic("a"), atomic("b")), not(atomic("a"))).absorption_law(&mut operations, Default::default());
         assert_eq!(expression, and(atomic("b"), not(atomic("a"))));
     }
 
diff --git a/src/routing/options.rs b/src/routing/options.rs
index 064e6eb..ba1a07c 100644
--- a/src/routing/options.rs
+++ b/src/routing/options.rs
@@ -2,15 +2,17 @@ use serde::Deserialize;
 use crate::expressions::truth_table::{Hide, Sort};
 use crate::utils::serialize::{ret_true, deserialize_bool};
 
+// TODO deserialize_bool should not be necessary
 #[derive(Deserialize)]
+#[serde(rename_all = "camelCase")]
 pub struct SimplifyOptions {
     #[serde(
         default = "ret_true",
         deserialize_with = "deserialize_bool"
     )]
     pub simplify: bool,
-    #[serde(default = "ret_true")]
-    pub case_sensitive: bool, // TODO: Implement case sensitivity
+    #[serde(default, deserialize_with = "deserialize_bool")]
+    pub ignore_case: bool,
 }
 
 #[derive(Deserialize, Default)]
diff --git a/src/routing/routes/simplify.rs b/src/routing/routes/simplify.rs
index b54d9e3..5836a9b 100644
--- a/src/routing/routes/simplify.rs
+++ b/src/routing/routes/simplify.rs
@@ -20,7 +20,7 @@ async fn simplify(Path(path): Path<String>, Query(query): Query<SimplifyOptions>
             let before = expression.to_string();
             let mut operations = vec![];
             if query.simplify {
-                (expression, operations) = expression.simplify();
+                (expression, operations) = expression.simplify(query.into());
             }
             SimplifyResponse {
                 before,
@@ -42,7 +42,7 @@ async fn simplify_and_table(Path(path): Path<String>, Query(query): Query<Simpli
             let before = expression.to_string();
             let mut operations = vec![];
             if query.simplify_options.simplify {
-                (expression, operations) = expression.simplify();
+                (expression, operations) = expression.simplify(query.simplify_options.into());
             }
             let truth_table = TruthTable::new(&expression, query.table_options);
             SimplifyResponse {