x  <- let(aa = 12 ) in aa ;
f() = let(aa = 12 ) in aa ;

pp(x);
pp(f());

=erro
 o anterior da' 12 e {} !
=cut

x  <- let(aa = 12 , b = 14) in b ;
f() = let(aa = 12 , b = 14) in b ;

pp(x);
pp(f());

=erro
 o anterior tb da'
=cut
a <- 12 ;
let (a=1)in a ;

=erro
 da 12!
=cut