Update closure-expr.md
> _ClosureParam_ :\
> &nbsp;&nbsp; [_OuterAttribute_]<sup>\*</sup> [_PatternNoTopAlt_]&nbsp;( `:` [_Type_] )<sup>?</sup>
-A *closure expression*, also know as a lambda expression or a lambda, defines a [closure type] and evaluates to a value of that type.
+A *closure expression*, also known as a lambda expression or a lambda, defines a [closure type] and evaluates to a value of that type.
The syntax for a closure expression is an optional `move` keyword, then a pipe-symbol-delimited (`|`) comma-separated list of [patterns], called the *closure parameters* each optionally followed by a `:` and a type, then an optional `->` and type, called the *return type*, and then an expression, called the *closure body operand*.
The optional type after each pattern is a type annotation for the pattern.
If there is a return type, the closure body must be a [block].
