Set s of identities between relators
(xa) a-1,
(yb) b-1,
(zc) c-1,
(yzd) d-1,
b-1 (yd) (yc-1) (yzb-1) (yzyc-1) dc-1 (zb-1) (zyc-1) (zyzb-1),
(xb) b-1 (ye-1) e-1,
(xc) c-1 (zf-1) f-1,
(xd) d-1 (yzyzyzyf-1) (yzyzyze-1) (yzyzyf-1) (yzyze-1) (yzyf-1) (yze-1) (yf-1) e-1,
(ya) a-1 (xe) e,
(za) a-1 (xf) f