?? tensor square of range of "opposite color bishop" on "checkered" infinite quadrant ... ???

a,b,c .... ac = bb ....

x,y .... xb = ya, xc = yb ... ???....

d "xx"
e "yx"
f "xy"
g "yy"

????? .....

??hmmm, so is this the example where ... ???the tensor square is not quite principal, the lizard's tail being a bit chewed off ??? .... ???.....