guard not implemented for lambda

the following code:
```
def czad(a) = lambda(b) if (a+b = 0) = a+b 

czad(2)(-2) | czad(3)(4) | czad(0)(0)
```
fails to compile:
```
[ERROR] Can't compile:
 0: def czad(a) = lambda(b) if (a+b = 0) = a+b #
                              ^--- Syntax error at line 0 column 26: LAMBDA LEFT_PAREN RIGHT_PAREN WILDCARD
 (error code 178)
 1:
 2: czad(2)(-2) | czad(3)(4) | czad(0)(0)
 3:
```
