P 63/M,NR.176*CB* 
LATT     1
SYMM    -Y,      X-Y,      Z
SYMM     Y-X,   -X,        Z
SYMM    -X,     -Y,    .5+Z
SYMM     Y,      Y-X,  .5+Z
SYMM     X-Y,    X,    .5+Z
    0 .6666 / 0 .6666 / 0 .25
    SONDER: X .LE. (1+Y)/2
    SONDER: Y .LE. MIN. (1-X,(1+X)/2)
    P 63/M,NR.176*CB*