Non-transitive region (3D viewer)
McDonald-shaped region: drag to rotate, scroll to zoom, click to select (pA,pB,pC).
Sampling: ready.
Region definition: 0<pA,pB,pC<1 and G_AB(pA,pB)>0, G_BC(pB,pC)>0, G_CA(pC,pA)>0. (These polynomials correspond to the classic length-3 example A=HHH, B=HTH, C=HHT.)