Hi,
How you know that perl interprets as foreach(@a if $A) but not (foreach @a) if $A?

I see any of constructs if/for/while can be written inside of parentheses, e.g. a simple ($A if $A) is a syntax error.

'and' and 'if' internally, as I understand, branch equivalently, only the direction differs. And the result of 'if' becomes not an expression, when the result of 'and' becomes an expression.