diff --git a/src/exec.c b/src/exec.c
index f1d208c..ce1c5de 100644
--- a/src/exec.c
+++ b/src/exec.c
@@ -39,10 +39,11 @@ AST* exec_exp(AST* ast, Scope* parent) {
             return ast_init(
                 AST_TYPE_NUM, ast_num_data_init(*(ASTNumData*)ast->data)
             );
-        case AST_TYPE_VREF: return exec_vref(ast, parent);
-        case AST_TYPE_VDEF: return exec_vdef(ast, parent);
-        case AST_TYPE_FDEF: return exec_fdef(ast, parent);
-        default:            printf("what\n"); exit(1);
+        case AST_TYPE_VREF:   return exec_vref(ast, parent);
+        case AST_TYPE_VDEF:   return exec_vdef(ast, parent);
+        case AST_TYPE_FDEF:   return exec_fdef(ast, parent);
+        case AST_TYPE_LAMBDA: return exec_lambda(ast, parent);
+        default:              printf("what\n"); exit(1);
     }
 }
 
@@ -79,7 +80,8 @@ AST* exec_call(AST* ast, Scope* parent) {
         case AST_TYPE_BIF:
             ASTBIFData bifdata = fdef->data;
             return bifdata(argc, argv, parent);
-        case AST_TYPE_FDEF: return exec_cf(fdef, argc, argv);
+        case AST_TYPE_FDEF:   return exec_cf(fdef, argc, argv);
+        case AST_TYPE_LAMBDA: return exec_lambda_call(fdef, argc, argv);
         default:
             return ast_init(AST_TYPE_EXC, ast_exc_data_init("Good job!", NULL));
     }
@@ -132,14 +134,29 @@ AST* exec_vref(AST* ast, Scope* parent) {
 AST* exec_fdef(AST* ast, Scope* parent) {
     ast->scope = scope_init(parent);
     ASTFDefData* fdef = (ASTFDefData*)ast->data;
-    log_dbgf("IS THIS SUSPICIOUS??? %i", fdef->body->type);
     AST* val = ast;
     char* key = fdef->name;
     scope_add(parent, key, val);
-    // TODO: Create lambda functions.
     return fdef->body; // Function definitions return function body.
 }
 
+AST* exec_lambda(AST* ast, Scope* parent) {
+    // Executing a lambda on its own with no arguments returns itself.
+    return ast;
+}
+
+AST* exec_lambda_call(AST* ast, size_t argc, AST** argv) {
+    Scope* callscope = scope_init(ast->scope);
+    ASTFDefData* lambda = (ASTFDefData*)ast->data;
+    for (int i = 0; i < argc; i++) {
+        char* key = ((ASTArgData*)lambda->argv[i]->data)->name;
+        AST* val = argv[i];
+        scope_add(callscope, key, val);
+    }
+
+    return exec_exp(lambda->body, callscope);
+}
+
 void exec_print(double n) { printf("= %lf\n", n); }
 
 inline void exec_new_scope(AST* ast, Scope* inherit) {
diff --git a/src/grammar.y b/src/grammar.y
index 4eb1508..973efe0 100644
--- a/src/grammar.y
+++ b/src/grammar.y
@@ -142,6 +142,15 @@ exp:
         $$ = ast_init(AST_TYPE_LAMBDA, ast_lambda_data_init(argc, argv, $5));
     }
 
+    /*
+    // Inline call.
+    | exp GROUPS arg GROUPE {
+        size_t argc = $3->ln;
+        AST** argv = $3->buf;
+        argarr_destroypsv($3);
+        $$ = ast_init(AST_TYPE_CALL, ($1, argc, argv));
+    }
+    */
 
     | BLOCKS block BLOCKE {
         $$ = ast_init(AST_TYPE_BLOCK, ast_block_data_init((AST**) $2->buf, $2->ln));
diff --git a/src/include/ast.h b/src/include/ast.h
index 9f2239d..ea6de51 100644
--- a/src/include/ast.h
+++ b/src/include/ast.h
@@ -86,13 +86,6 @@ ASTBIFData* ast_bif_data_init(AST* fn(size_t, AST**, Scope*));
 // Destroy an `ASTBIFData`.
 void ast_bif_data_destroy(ASTBIFData* bif);
 
-/*
- * // A list of arguments.
-typedef struct {
-    size_t argc;
-    AST** argv;
-} Args;
-*/
 // A call (to a function).
 typedef struct {
     char* to; // What the call's to.
diff --git a/src/include/exec.h b/src/include/exec.h
index 8836e21..bd7ddc1 100644
--- a/src/include/exec.h
+++ b/src/include/exec.h
@@ -20,6 +20,10 @@ AST* exec_vdef(AST* ast, Scope* parent);
 AST* exec_vref(AST* ast, Scope* parent);
 // Execute a function definition.
 AST* exec_fdef(AST* ast, Scope* parent);
+// Execute a lambda expression.
+AST* exec_lambda(AST* ast, Scope* parent);
+// Execute a lambda call.
+AST* exec_lambda_call(AST* ast, size_t argc, AST** argv);
 // Print the result of an execution.
 void exec_print(double n);