Occurred error args in define expression

[m11o]

Hi, This project is fantastic! I studied scheme lang by using scheme.wasm.html. But, there is a bug not to use define expression in the site. Please check it.

Expected

> (define (square a) (* a a))
; defined

Actually

> (define (square a) (* a a))
<error args (square a) (* a a)>

Version: v0.1-136-gb5ce0b8