module twoinhaf
Title 'Find Two Xs and an empty cell in a row, column, or diagonal'
"TWOINHAF device 'P22V10'; 

" Inputs and Outputs
X11, X12, X13, X21, X22, X23, X31, X32, X33     pin 1..9;
Y11, Y12, Y13, Y21, Y22, Y23, Y31, Y32, Y33     pin 10..11, 13..15, 20..23;
MOVE3..MOVE0                                    pin 16..19 istype 'com';

" MOVE output encodings
MOVE   = [MOVE3..MOVE0];
MOVE11 = [1,0,0,0];
MOVE12 = [0,1,0,0];
MOVE13 = [0,0,1,0];
MOVE21 = [0,0,0,1];
MOVE22 = [1,1,0,0];
MOVE23 = [0,1,1,1];
MOVE31 = [1,0,1,1];
MOVE32 = [1,1,0,1];
MOVE33 = [1,1,1,0];
NONE   = [0,0,0,0];

" Find moves in rows.  Rxy ==> a move exists in cell xy
R11 = X12 & X13 & !X11 & !Y11;
R12 = X11 & X13 & !X12 & !Y12;
R13 = X11 & X12 & !X13 & !Y13; 
R21 = X22 & X23 & !X21 & !Y21;
R22 = X21 & X23 & !X22 & !Y22;
R23 = X21 & X22 & !X23 & !Y23;
R31 = X32 & X33 & !X31 & !Y31;
R32 = X31 & X33 & !X32 & !Y32;
R33 = X31 & X32 & !X33 & !Y33;

" Find moves in columns.  Cxy ==> a move exists in cell xy
C11 = X21 & X31 & !X11 & !Y11;
C12 = X22 & X32 & !X12 & !Y12;
C13 = X23 & X33 & !X13 & !Y13; 
C21 = X11 & X31 & !X21 & !Y21;
C22 = X12 & X32 & !X22 & !Y22;
C23 = X13 & X33 & !X23 & !Y23;
C31 = X11 & X21 & !X31 & !Y31;
C32 = X12 & X22 & !X32 & !Y32;
C33 = X13 & X23 & !X33 & !Y33;

" Find moves in diagonals.  Dxy or Exy ==> a move exists in cell xy
D11 = X22 & X33 & !X11 & !Y11;
D22 = X11 & X33 & !X22 & !Y22;
D33 = X11 & X22 & !X33 & !Y33;
E13 = X22 & X31 & !X13 & !Y13;
E22 = X13 & X31 & !X22 & !Y22;
E31 = X13 & X22 & !X31 & !Y31;

" Combine moves for each cell.  Gxy ==> a move exists in cell xy
G11 = R11 # C11 # D11;
G12 = R12 # C12;
G13 = R13 # C13 # E13;
G21 = R21 # C21;
G22 = R22 # C22 # D22 # E22;
G23 = R23 # C23;
G31 = R31 # C31 # E31;
G32 = R32 # C32;
G33 = R33 # C33 # D33;

Equations
" Only look in cells 11, 12, 13, 21, 22
WHEN G22 THEN MOVE= MOVE22;
ELSE WHEN G11 THEN MOVE = MOVE11;
ELSE WHEN G13 THEN MOVE = MOVE13;
"ELSE WHEN G31 THEN MOVE = MOVE31;
"ELSE WHEN G33 THEN MOVE = MOVE33;
ELSE WHEN G12 THEN MOVE = MOVE12;
ELSE WHEN G21 THEN MOVE = MOVE21;
"ELSE WHEN G23 THEN MOVE = MOVE23;
"ELSE WHEN G32 THEN MOVE = MOVE32;
ELSE MOVE = NONE;

end twoinhaf