diff --git a/src/interpreter.cpp b/src/interpreter.cpp
index 4699ab3..e0ac740 100644
--- a/src/interpreter.cpp
+++ b/src/interpreter.cpp
@@ -285,9 +285,6 @@ EvalResult eval(Node &ast, Memory &memory) {
                 string typeName = get<string>(typeTok.data);
                 string identifier = get<string>(identifierTok.data);
 
-                if (memory.contains_top(identifier))
-                    throw RuntimeError("Already defined identifier \""+identifier+"\"", identifierTok.pos);
-
                 memory.declare(identifier, string_to_type(typeName));
                 
                 return {};
@@ -299,9 +296,6 @@ EvalResult eval(Node &ast, Memory &memory) {
                 string identifier = get<string>(identifierTok.data);
                 EvalResult value = eval(node.children[2], memory);
 
-                if (memory.contains_top(identifier))
-                    throw RuntimeError("Already defined identifier \""+identifier+"\"", identifierTok.pos);
-
                 Type type = string_to_type(typeName);
                 memory.declare(identifier, type);
                 
@@ -319,9 +313,6 @@ EvalResult eval(Node &ast, Memory &memory) {
                 string identifier = get<string>(identifierTok.data);
                 EvalResult value = eval(node.children[1], memory);
 
-                if (!memory.contains(identifier))
-                    throw RuntimeError("Unknown identifier \""+identifier+"\"", identifierTok.pos);
-
                 Type type = memory.get(identifier).type;
 
                 if (type == Type::Int) {
@@ -337,9 +328,6 @@ EvalResult eval(Node &ast, Memory &memory) {
                 Token identifierTok = get<Token>(node.children[0]);
                 string identifier = get<string>(identifierTok.data);
 
-                if (!memory.contains(identifier))
-                    throw RuntimeError("Unknown identifier \""+identifier+"\"", identifierTok.pos);
-
                 MemoryVar& var = memory.get(identifier);
 
                 if (!var.initialized) {
@@ -357,9 +345,6 @@ EvalResult eval(Node &ast, Memory &memory) {
                 Token identifierTok = get<Token>(node.children[0]);
                 string identifier = get<string>(identifierTok.data);
 
-                if (!memory.contains(identifier))
-                    throw RuntimeError("Unknown identifier \""+identifier+"\"", identifierTok.pos);
-
                 MemoryVar& var = memory.get(identifier);
 
                 if (!var.initialized) {
@@ -378,9 +363,6 @@ EvalResult eval(Node &ast, Memory &memory) {
                 Token identifierTok = get<Token>(node.children[0]);
                 string identifier = get<string>(identifierTok.data);
 
-                if (!memory.contains(identifier))
-                    throw RuntimeError("Unknown identifier \""+identifier+"\"", identifierTok.pos);
-
                 MemoryVar& var = memory.get(identifier);
 
                 if (!var.initialized) {
@@ -398,9 +380,6 @@ EvalResult eval(Node &ast, Memory &memory) {
                 Token identifierTok = get<Token>(node.children[0]);
                 string identifier = get<string>(identifierTok.data);
 
-                if (!memory.contains(identifier))
-                    throw RuntimeError("Unknown identifier \""+identifier+"\"", identifierTok.pos);
-
                 MemoryVar& var = memory.get(identifier);
 
                 if (!var.initialized) {
@@ -435,9 +414,6 @@ EvalResult eval(Node &ast, Memory &memory) {
             } break;
             case TokenType::Identifier: {
                 string identifier = get<string>(token.data);
-
-                if (!memory.contains(identifier))
-                    throw RuntimeError("Unknown identifier \""+identifier+"\"", token.pos);
                 
                 MemoryVar& var = memory.get(identifier);