@Fergus: in fact the second line of this block just should be deleted.
alias s c S C;
alias c Z C Z;
That wasn't what needed to be fixed. When I changed the setlegal commands in the stalemated subroutine to take strings instead of coordinate arrays as arguments, I didn't make sure they used aliases. I have now fixed that.
That wasn't what needed to be fixed. When I changed the setlegal commands in the stalemated subroutine to take strings instead of coordinate arrays as arguments, I didn't make sure they used aliases. I have now fixed that.