[gnugo-devel] CC205

[Daniel Bump]

The compiler complains about the constraint in CC205:

; (!(!x_somewhere(c) && !o_somewhere(c) && xcut(c) 
;    || !x_somewhere(d) && !o_somewhere(c) && xcut(d)) && attack(A))
; || (!ko(B) && !xcut(B) && !safe_xmove(B))

The || and && are close in precedence so a || b && c should
be parenthesized, in this case

; (!((!x_somewhere(c) && !o_somewhere(c) && xcut(c))
;    || (!x_somewhere(d) && !o_somewhere(c) && xcut(d))) && attack(A))
; || (!ko(B) && !xcut(B) && !safe_xmove(B))

This can be simplified using de Morgan's laws,
!(a && b) = !a || !b and !(a || b) = !a && !b.

; (((x_somewhere(c) || o_somewhere(c) || !xcut(c))
;    && (x_somewhere(d) || o_somewhere(c) || !xcut(d))) && attack(A))
; || (!ko(B) && !xcut(B) && !safe_xmove(B))

I suppose we could make xcut return false if the
intersection is not empty.c. Maybe a comment is in order
to explain the meaning of the constraint.

Dan