Index: polemy/parse.d
==================================================================
--- polemy/parse.d
+++ polemy/parse.d
@@ -65,17 +65,27 @@
 					goto asExpression;
 				}
 			}
 			immutable LexPosition varpos = (lex.empty ? null : lex.front.pos);
 			string var = eatId("after "~kwd,true);
-			eat("=", "after "~kwd);
-			kwd = (kwd[0]=='@' ? kwd : ""); // "let, var, def ==> neutral layer"
-			auto e = E(0);
-			if( tryEat(";") && !lex.empty && (lex.front.quoted || !["}",")","]"].canFind(lex.front.str)) )
-				return new LetExpression(pos, var, kwd, e, Body());
-			else
-				return new LetExpression(pos, var, kwd, e, new VarExpression(varpos, var));
+			// [TODO] refactor. only auto e = ... differ
+			if(tryEat("(")) {
+				kwd = (kwd[0]=='@' ? kwd : ""); // "let, var, def ==> neutral layer"
+				auto e = parseLambdaAfterOpenParen(varpos);
+				if( tryEat(";") && !lex.empty && (lex.front.quoted || !["}",")","]"].canFind(lex.front.str)) )
+					return new LetExpression(pos, var, kwd, e, Body());
+				else
+					return new LetExpression(pos, var, kwd, e, new VarExpression(varpos, var));
+			} else {
+				eat("=", "after "~kwd);
+				kwd = (kwd[0]=='@' ? kwd : ""); // "let, var, def ==> neutral layer"
+				auto e = E(0);
+				if( tryEat(";") && !lex.empty && (lex.front.quoted || !["}",")","]"].canFind(lex.front.str)) )
+					return new LetExpression(pos, var, kwd, e, Body());
+				else
+					return new LetExpression(pos, var, kwd, e, new VarExpression(varpos, var));
+			}
 		}
 		else
 		{
 		asExpression:
 			auto e = E(0);
@@ -202,26 +212,31 @@
 			);
 		}
 		if( tryEat("fun") || tryEat("\u03BB") )
 		{
 			eat("(", "after fun");
-			string[] params;
-			while( !tryEat(")") )
-			{
-				params ~= eatId("for function parameter");
-				if( !tryEat(",") ) {
-					eat(")", "after function parameters");
-					break;
-				}
-			}
-			eat("{", "after function parameters");
-			auto funbody = Body();
-			eat("}", "after function body");
-			return new FunLiteral(pos, params, funbody);
+			return parseLambdaAfterOpenParen(pos);
 		}
 		scope(exit) lex.popFront;
 		return new VarExpression(pos, lex.front.str);
+	}
+
+	AST parseLambdaAfterOpenParen(immutable LexPosition pos)
+	{
+		string[] params;
+		while( !tryEat(")") )
+		{
+			params ~= eatId("for function parameter");
+			if( !tryEat(",") ) {
+				eat(")", "after function parameters");
+				break;
+			}
+		}
+		eat("{", "after function parameters");
+		auto funbody = Body();
+		eat("}", "after function body");
+		return new FunLiteral(pos, params, funbody);
 	}
 
 private:
 	Lexer lex;
 	this(Lexer lex) { this.lex = lex; }
@@ -330,5 +345,15 @@
 	assert_throw!UnexpectedEOF(parseString(`var`));
 	assert_throw!ParseException(parseString(`@val x ==`));
 	assert_throw!ParseException(parseString(`if(){1}`));
 	assert_throw!UnexpectedEOF(parseString(`f(`));
 }
+
+unittest
+{
+	mixin EasyAST;
+	assert_eq(parseString(`def foo(x) { x+1 }; foo`),
+		let("foo", "",
+			fun(["x"], call(var("+"), var("x"), intl(1))),
+			var("foo"))
+	);
+}

ADDED   sample/fib.pmy
Index: sample/fib.pmy
==================================================================
--- sample/fib.pmy
+++ sample/fib.pmy
@@ -0,0 +1,15 @@
+def fib(x)
+{
+	if( x < 2 ) { 1 }
+	else        { fib(x-1) + fib(x-2) }
+};
+
+let upto = λ(n, f){
+	if( n > 0 ){ upto(n-1,f) };
+	f(n)
+};
+
+var compose = fun(f,g){ fun(x){f(g(x))} };
+var "<<" = compose;
+
+upto(16, print<<fib);

ADDED   sample/helloworld.pmy
Index: sample/helloworld.pmy
==================================================================
--- sample/helloworld.pmy
+++ sample/helloworld.pmy
@@ -0,0 +1,1 @@
+print("Hello, World!")

ADDED   sample/plusminus.pmy
Index: sample/plusminus.pmy
==================================================================
--- sample/plusminus.pmy
+++ sample/plusminus.pmy
@@ -0,0 +1,6 @@
+@s "+" = fun(x, y) {@v(
+	@s(x) - @s(y)
+)};
+
+print( 1 + 2 );
+print( @s(1 + 2) );