Let x, y and z be given.

Assume Hx Hy Hz Hy0 H1.

Apply mul_SNo_nonzero_cancel y (x :/: y) z Hy Hy0 (SNo_div_SNo x y Hx Hy) Hz to the current goal.

We will prove y * (x :/: y) = y * z.

rewrite the current goal using mul_div_SNo_invR x y Hx Hy Hy0 (from left to right).

An exact proof term for the current goal is H1.

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