s

Set s of identities between relators

(^xa)a^-1,

(^yb) b^-1,

(^yxyc) (^yx²yc) (^ya) (^{yx^-2}b) (^{yx^-2}c^-1) a^-1 (^x²c) cb^-1 (^y³c) (^y²a^-1) (^y²c)