diff --git a/doc/roza.bnf b/doc/roza.bnf
index ac9fcd6..f918b08 100644
--- a/doc/roza.bnf
+++ b/doc/roza.bnf
@@ -1,6 +1,10 @@
 MOD ::= EXPR*
 EXPR ::=
 | ASSERT
-| BUILTIN
+| EQNE
 ASSERT ::= assert EXPR
+EQNE ::=
+| BUILTIN
+| BUILTIN eq BUILTIN
+| BUILTIN ne BUILTIN
 BUILTIN ::= num | bool | str
diff --git a/lib/compiler.c b/lib/compiler.c
index bbaf08e..a8b0455 100644
--- a/lib/compiler.c
+++ b/lib/compiler.c
@@ -64,6 +64,19 @@ void compiler_run(compiler_t* compiler, node_t* node)
       mod_push_instr(compiler->mod, OP_ASSERT, RZ_NO_PARAM);
     } break;
 
+    case NODE_NE:
+    case NODE_EQ: {
+      assert(node->children.size == 2);
+
+      for (size_t i=0; i<node->children.size; i++)
+        {
+          compiler_run(compiler, node_child(node, i));
+        }
+
+      mod_push_instr(compiler->mod,
+                     node->type == NODE_EQ ? OP_EQ : OP_NE, RZ_NO_PARAM);
+    } break;
+
     default: {
       fprintf(stderr, "Cannot compile unknown node '%s'",
               NodeTypeStr[node->type]);
diff --git a/lib/lexer.c b/lib/lexer.c
index 7bb5543..d0bd370 100644
--- a/lib/lexer.c
+++ b/lib/lexer.c
@@ -1,10 +1,16 @@
 #include "lexer.h"
 #include "lib/commons.h"
 
-#define RZ_KEYWORD(KW, NODE, VAL)                               \
-  {                                                             \
-    node_t* kw = lexer_try_new_keyword(lexer, KW, NODE, VAL);   \
-    if (kw) { lexer_skip_spaces(lexer); return kw; }            \
+#define RZ_KEYWORD(KW, NODE, VAL)                                       \
+  {                                                                     \
+    node_t* kw = lexer_try_new_keyword(lexer, KW, NODE, VAL, 1);        \
+    if (kw) { lexer_skip_spaces(lexer); return kw; }                    \
+  }
+
+#define RZ_TEXT(KW, NODE, VAL)                                       \
+  {                                                                     \
+    node_t* kw = lexer_try_new_keyword(lexer, KW, NODE, VAL, 0);        \
+    if (kw) { lexer_skip_spaces(lexer); return kw; }                    \
   }
 
 void lexer_init(lexer_t* lexer, char const* source, err_t* err)
@@ -30,6 +36,11 @@ node_t* lexer_try_new_next(lexer_t* lexer)
 
   lexer_skip_spaces(lexer);
 
+  // Text
+  // ====
+  RZ_TEXT("==", NODE_EQ, 0);
+  RZ_TEXT("!=", NODE_NE, 0);
+
   // Keywords
   // ========
   RZ_KEYWORD("true", NODE_BOOL, 1);
@@ -156,7 +167,8 @@ void lexer_skip_spaces(lexer_t* lexer)
 }
 
 node_t* lexer_try_new_keyword(lexer_t* lexer, char* kw,
-                              NodeType type, int has_value)
+                              NodeType type, int has_value,
+                              int is_kw)
 {
   assert(lexer);
   assert(kw);
@@ -182,7 +194,7 @@ node_t* lexer_try_new_keyword(lexer_t* lexer, char* kw,
           int next_idx = lexer->cursor + len;
 
           if (next_idx < strlen(lexer->source)
-              && !isspace(lexer->source[next_idx]))
+              && (is_kw && !lexer_is_sep(lexer, next_idx)))
             {
               return NULL;
             }
@@ -272,3 +284,23 @@ node_t* lexer_try_new_str(lexer_t* lexer)
 
   return tok;
 }
+
+int lexer_is_sep(lexer_t* lexer, size_t idx)
+{
+  assert(lexer);
+
+  if (idx >= strlen(lexer->source))
+    {
+      return 1;
+    }
+
+  char c = lexer->source[idx];
+
+  if (isspace(c))
+    {
+      return 1;
+    }
+
+  return c == '='
+    || c == '!';
+}
diff --git a/lib/lexer.h b/lib/lexer.h
index 1ec7f29..4034b1b 100644
--- a/lib/lexer.h
+++ b/lib/lexer.h
@@ -20,8 +20,11 @@ NodeType lexer_peek(lexer_t* lexer, int lookahead);
 void lexer_skip_spaces(lexer_t* lexer);
 
 node_t* lexer_try_new_keyword(lexer_t* lexer, char* kw,
-                              NodeType type, int has_value);
+                              NodeType type, int has_value,
+                              int is_kw);
 
 node_t* lexer_try_new_str(lexer_t* lexer);
 
+int lexer_is_sep(lexer_t* lexer, size_t idx);
+
 #endif
diff --git a/lib/loader.c b/lib/loader.c
index dd9268c..120edaf 100644
--- a/lib/loader.c
+++ b/lib/loader.c
@@ -1,4 +1,5 @@
 #include "lexer.h"
+#include "lib/commons.h"
 #include "parser.h"
 #include "loader.h"
 #include "compiler.h"
@@ -63,6 +64,15 @@ int loader_ldfile(loader_t* loader, char const* path, int debug)
 
   node_t* node = parser_try_new_tree(&parser);
 
+  if (debug)
+  {
+    char msg[RZ_STR_LIMIT];
+    node_str(node, msg, RZ_STR_LIMIT);
+
+    printf("\n======== AST ========\n");
+    printf("%s\n", msg);
+  }
+
   if (node)
     {
       mod_t mod;
@@ -102,7 +112,7 @@ int loader_ldfile(loader_t* loader, char const* path, int debug)
       // execute
       {
         vm_t vm;
-        vm_init(&vm, &err);
+        vm_init(&vm, &tysy, &err);
 
         int status = vm_exec_mod(&vm, &mod);
 
diff --git a/lib/node.h b/lib/node.h
index 9ed6c9e..0f0c81a 100644
--- a/lib/node.h
+++ b/lib/node.h
@@ -6,7 +6,8 @@
 #define NODE_TYPE(G)                            \
   G(NODE_MOD),                                  \
     G(NODE_NUM), G(NODE_BOOL), G(NODE_STR),     \
-    G(NODE_ASSERT)
+    G(NODE_ASSERT),                             \
+    G(NODE_EQ), G(NODE_NE)
 
 RZ_ENUM_H(NodeType, NODE_TYPE);
 
diff --git a/lib/opcodes.h b/lib/opcodes.h
index cea0b73..88d93ec 100644
--- a/lib/opcodes.h
+++ b/lib/opcodes.h
@@ -5,7 +5,8 @@
 
 #define OPCODES(G)                              \
   G(OP_ASSERT),                                 \
-    G(OP_PUSH), G(OP_POP)
+    G(OP_PUSH), G(OP_POP),                      \
+    G(OP_EQ), G(OP_NE)
 
 RZ_ENUM_H(Opcode, OPCODES);
 
diff --git a/lib/parser.c b/lib/parser.c
index 77a3541..684de5a 100644
--- a/lib/parser.c
+++ b/lib/parser.c
@@ -61,7 +61,7 @@ node_t* parser_try_new_expr(parser_t* parser)
       return parser_try_new_assert(parser);
     }
 
-  return parser_try_new_builtin(parser);
+  return parser_try_new_eqne(parser);
 }
 
 node_t* parser_try_new_assert(parser_t* parser)
@@ -77,6 +77,33 @@ node_t* parser_try_new_assert(parser_t* parser)
   return node;
 }
 
+node_t* parser_try_new_eqne(parser_t* parser)
+{
+  assert(parser);
+  node_t* lhs = parser_try_new_builtin(parser);
+
+  while (1)
+    {
+      NodeType next_type = lexer_peek(parser->lexer, 1);
+
+      if (next_type == NODE_EQ || next_type == NODE_NE)
+        {
+          node_t* node = lexer_try_new_next(parser->lexer);
+
+          node_add_new_child(node, lhs);
+          node_add_new_child(node, parser_try_new_builtin(parser));
+
+          lhs = node;
+        }
+      else
+        {
+          break;
+        }
+    }
+
+  return lhs;
+}
+
 node_t* parser_try_new_builtin(parser_t* parser)
 {
   assert(parser);
diff --git a/lib/parser.h b/lib/parser.h
index f300764..52ad5ba 100644
--- a/lib/parser.h
+++ b/lib/parser.h
@@ -17,6 +17,7 @@ node_t* parser_try_new_tree(parser_t* parser);
 node_t* parser_try_new_mod(parser_t* parser);
 node_t* parser_try_new_expr(parser_t* parser);
 node_t* parser_try_new_assert(parser_t* parser);
+node_t* parser_try_new_eqne(parser_t* parser);
 node_t* parser_try_new_builtin(parser_t* parser);
 
 node_t* parser_try_new_consume(parser_t* parser, NodeType type);
diff --git a/lib/prepass.c b/lib/prepass.c
index 1159a4b..2ee845b 100644
--- a/lib/prepass.c
+++ b/lib/prepass.c
@@ -24,7 +24,9 @@ void prepass_run(prepass_t* prepass, node_t* node)
     case NODE_NUM:
     case NODE_STR:
     case NODE_BOOL:
-    case NODE_ASSERT:{
+    case NODE_ASSERT:
+    case NODE_EQ:
+    case NODE_NE: {
       for (size_t i=0; i<node->children.size; i++)
         {
           prepass_run(prepass, (node_t*) node->children.data[i]);
diff --git a/lib/vm.c b/lib/vm.c
index 15b4875..56b991b 100644
--- a/lib/vm.c
+++ b/lib/vm.c
@@ -1,8 +1,9 @@
 #include "vm.h"
 #include "lib/commons.h"
+#include "lib/mod.h"
 #include "lib/type.h"
 
-void vm_init(vm_t* vm, err_t* err)
+void vm_init(vm_t* vm, tysy_t* tysy, err_t* err)
 {
   assert(vm);
 
@@ -10,6 +11,7 @@ void vm_init(vm_t* vm, err_t* err)
   vm->bp = 0;
   vm->sp = 0;
 
+  vm->tysy = tysy;
   vm->err = err;
 }
 
@@ -18,6 +20,24 @@ void vm_free(vm_t* vm)
   assert(vm);
 }
 
+void vm_push_value(vm_t* vm, mod_t* mod, value_t* value)
+{
+  assert(vm);
+  assert(value);
+
+  param_t param = mod_push_new_value(mod, value);
+  vm_push(vm, param);
+}
+
+void vm_push(vm_t* vm, param_t param)
+{
+  assert(vm);
+  assert(vm->sp + 1 < RZ_STACK_LIMIT);
+
+  vm->stack[vm->sp] = param;
+  vm->sp++;
+}
+
 param_t vm_pop(vm_t* vm)
 {
   assert(vm);
@@ -111,6 +131,54 @@ int vm_exec_instr(vm_t* vm, mod_t* mod, Opcode op, param_t param)
 
     } break;
 
+    case OP_NE:
+    case OP_EQ: {
+      int l = vm_pop(vm);
+      int r = vm_pop(vm);
+      assert(l != -1);
+      assert(r != -1);
+
+      value_t* rhs = mod->values.data[l];
+      value_t* lhs = mod->values.data[r];
+
+      int same_type = lhs->type->kind == rhs->type->kind;
+      int type = lhs->type->kind;
+
+      int eq = 0;
+
+      if (same_type)
+        {
+          if (type == TYPE_NUM)
+            {
+              eq = lhs->value.num == rhs->value.num;
+            }
+          else if (type == TYPE_BOOL)
+            {
+              eq = lhs->value.bool == rhs->value.bool;
+            }
+          else if (type == TYPE_STR)
+            {
+              eq = strcmp(lhs->value.str, rhs->value.str) == 0;
+            }
+          else
+            {
+              fprintf(stderr, "Cannot test equality on unknown type '%s'.\n",
+                      TypeKindStr[type]);
+              abort();
+            }
+        }
+
+      value_t* res = tysy_new_bool(vm->tysy,
+                                   (op == OP_EQ
+                                    ? (same_type && eq)
+                                    : (!same_type || !eq)),
+                                   rhs->line);
+
+      vm_push_value(vm, mod, res);
+
+      vm->pc++;
+    } break;
+
     default: {
       fprintf(stderr, "Cannot execute unknown opcode '%s'.\n",
               OpcodeStr[op]);
diff --git a/lib/vm.h b/lib/vm.h
index 9660207..af410ff 100644
--- a/lib/vm.h
+++ b/lib/vm.h
@@ -5,8 +5,10 @@
 #include "opcodes.h"
 #include "mod.h"
 #include "err.h"
+#include "tysy.h"
 
 typedef struct {
+  tysy_t* tysy;
   param_t stack[RZ_STACK_LIMIT];
   size_t pc;
   size_t bp;
@@ -15,9 +17,11 @@ typedef struct {
   err_t* err;
 } vm_t;
 
-void vm_init(vm_t* vm, err_t* err);
+void vm_init(vm_t* vm, tysy_t* tysy, err_t* err);
 void vm_free(vm_t* vm);
 
+void vm_push_value(vm_t* vm, mod_t* mod, value_t* value);
+void vm_push(vm_t* vm, param_t param);
 param_t vm_pop(vm_t* vm);
 
 size_t vm_stack_str(vm_t* vm, char* buffer, size_t size);
diff --git a/tests/acceptances/cmp.roza b/tests/acceptances/cmp.roza
new file mode 100644
index 0000000..edb7507
--- /dev/null
+++ b/tests/acceptances/cmp.roza
@@ -0,0 +1,13 @@
+assert 5 == 5
+assert 3 != 5
+
+assert true == true
+assert false == false
+assert false != true
+
+assert "hello" == "hello"
+assert "world" != "hello"
+
+assert 7 != "hello"
+assert false != 23
+assert "bim" != true
diff --git a/tests/units/lexer.c b/tests/units/lexer.c
index 855540f..183f875 100644
--- a/tests/units/lexer.c
+++ b/tests/units/lexer.c
@@ -8,13 +8,13 @@ static void test_lexer_ok(char const* oracle, char const* source)
   lexer_init(&lex, source, NULL);
 
   node_t* tok = lexer_try_new_next(&lex);
-  cr_assert(tok != NULL);
+  cr_assert(tok != NULL, "error -> %s", source);
 
   size_t const SZ = 512;
   char str[SZ];
   node_str(tok, str, SZ);
 
-  cr_assert_str_eq(str, oracle);
+  cr_assert_str_eq(str, oracle, "error -> %s", source);
 
   node_free(tok);
   lexer_free(&lex);
@@ -30,7 +30,7 @@ static void test_lexer_ko(char const* source)
 
   node_t* tok = lexer_try_new_next(&lex);
 
-  cr_assert(tok == NULL);
+  cr_assert(tok == NULL, "error -> %s", source);
   cr_assert(err.size > 0);
 
   err_free(&err);
@@ -48,7 +48,7 @@ static void test_lexer(char const* source, size_t n, ...)
   for (size_t i=0; i<n; i++)
     {
       node_t* tok = lexer_try_new_next(&lexer);
-      cr_assert(NULL != tok);
+      cr_assert(NULL != tok, "error -> %s", source);
 
       size_t const SZ = 256;
       char tok_str[SZ];
@@ -109,3 +109,19 @@ Test(lexer, str) {
 Test(lexer, assert) {
   test_lexer("assert", 1, "ASSERT");
 }
+
+Test(lexer, cmp) {
+  test_lexer("== !=", 2,
+             "EQ",
+             "NE");
+
+  test_lexer("false==true", 3,
+             "BOOL[false]",
+             "EQ",
+             "BOOL[true]");
+
+  test_lexer("false!=true", 3,
+             "BOOL[false]",
+             "NE",
+             "BOOL[true]");
+}
diff --git a/tests/units/parser.c b/tests/units/parser.c
index 3a34166..25c7f3b 100644
--- a/tests/units/parser.c
+++ b/tests/units/parser.c
@@ -15,7 +15,7 @@ static void test_parser_ok(char const* oracle, char const* source)
 
   node_t* node = parser_try_new_tree(&parser);
 
-  cr_assert(NULL != node);
+  cr_assert(NULL != node, "error -> %s", source);
 
   size_t const SZ = 256;
   char msg[SZ];
@@ -71,3 +71,8 @@ Test(parser, assert) {
   test_parser_ok("MOD(ASSERT(BOOL[false]))", " assert false ");
   test_parser_ok("MOD(ASSERT(BOOL[true]))", " assert true ");
 }
+
+Test(parser, eqne) {
+  test_parser_ok("MOD(EQ(NUM[3],NUM[3]))", " 3 == 3  ");
+  test_parser_ok("MOD(NE(NUM[3],NUM[3]))", " 3 != 3  ");
+}