NO Non-Confluence Proof

Non-Confluence Proof

by Hakusan

Input

The rewrite relation of the following TRS is considered.

f(c) a
f(a) c
c f(h(a,h(f(c),c)))
h(f(c),f(b)) f(h(a,c))

Proof

1 Non-Joinable Fork

The system is not confluent due to the following forking derivations.

t0 = f(c)
1 f(f(h(a,h(f(c),c))))
= t1

t0 = f(c)
ε a
= t1

The two resulting terms cannot be joined for the following reason:

Tool configuration

Hakusan