YES Confluence Proof

Confluence Proof

by csi

Input

The rewrite relation of the following TRS is considered.

c f(a,h(b))
f(h(f(f(a,a),h(a))),g(f(x,g(b)))) c
c c
g(g(a)) f(h(g(f(c,c))),f(f(g(c),a),g(f(a,a))))
f(x,y) f(y,x)

Proof

1 Redundant Rules Transformation

To prove that the TRS is (non-)confluent, we show (non-)confluence of the following modified system:

f(x,y) f(y,x)
g(g(a)) f(h(g(f(c,c))),f(f(g(c),a),g(f(a,a))))
f(h(f(f(a,a),h(a))),g(f(x,g(b)))) c
c f(a,h(b))

All redundant rules that were added or removed can be simulated in 1 steps .

1.1 Redundant Rules Transformation

To prove that the TRS is (non-)confluent, we show (non-)confluence of the following modified system:

f(x,y) f(y,x)
g(g(a)) f(h(g(f(c,c))),f(f(g(c),a),g(f(a,a))))
f(h(f(f(a,a),h(a))),g(f(x,g(b)))) c
c f(a,h(b))
f(h(f(f(a,a),h(a))),g(f(g(b),x))) c
f(h(f(h(a),f(a,a))),g(f(x,g(b)))) c
f(g(f(x,g(b))),h(f(f(a,a),h(a)))) c
f(g(f(x61,g(b))),h(f(f(a,a),h(a)))) c

All redundant rules that were added or removed can be simulated in 2 steps .

1.1.1 Redundant Rules Transformation

To prove that the TRS is (non-)confluent, we show (non-)confluence of the following modified system:

f(g(f(x61,g(b))),h(f(f(a,a),h(a)))) c
f(h(f(h(a),f(a,a))),g(f(x,g(b)))) c
f(h(f(f(a,a),h(a))),g(f(g(b),x))) c
c f(a,h(b))
f(h(f(f(a,a),h(a))),g(f(x,g(b)))) c
g(g(a)) f(h(g(f(c,c))),f(f(g(c),a),g(f(a,a))))
f(x,y) f(y,x)

All redundant rules that were added or removed can be simulated in 1 steps .

1.1.1.1 Redundant Rules Transformation

To prove that the TRS is (non-)confluent, we show (non-)confluence of the following modified system:

f(g(f(x61,g(b))),h(f(f(a,a),h(a)))) c
f(h(f(h(a),f(a,a))),g(f(x,g(b)))) c
f(h(f(f(a,a),h(a))),g(f(g(b),x))) c
c f(a,h(b))
f(h(f(f(a,a),h(a))),g(f(x,g(b)))) c
g(g(a)) f(h(g(f(c,c))),f(f(g(c),a),g(f(a,a))))
f(x,y) f(y,x)
f(h(f(h(a),f(a,a))),g(f(g(b),x))) c
f(g(f(g(b),x)),h(f(f(a,a),h(a)))) c
f(g(f(x,g(b))),h(f(h(a),f(a,a)))) c
f(g(f(x61,g(b))),h(f(h(a),f(a,a)))) c
f(g(f(g(b),x61)),h(f(f(a,a),h(a)))) c
f(g(f(g(b),x383)),h(f(f(a,a),h(a)))) c
f(g(f(x381,g(b))),h(f(h(a),f(a,a)))) c

All redundant rules that were added or removed can be simulated in 2 steps .

1.1.1.1.1 Redundant Rules Transformation

To prove that the TRS is (non-)confluent, we show (non-)confluence of the following modified system:

f(g(f(x381,g(b))),h(f(h(a),f(a,a)))) c
f(g(f(g(b),x383)),h(f(f(a,a),h(a)))) c
f(h(f(h(a),f(a,a))),g(f(g(b),x))) c
f(x,y) f(y,x)
g(g(a)) f(h(g(f(c,c))),f(f(g(c),a),g(f(a,a))))
f(h(f(f(a,a),h(a))),g(f(x,g(b)))) c
c f(a,h(b))
f(h(f(f(a,a),h(a))),g(f(g(b),x))) c
f(h(f(h(a),f(a,a))),g(f(x,g(b)))) c
f(g(f(x61,g(b))),h(f(f(a,a),h(a)))) c

All redundant rules that were added or removed can be simulated in 1 steps .

1.1.1.1.1.1 Redundant Rules Transformation

To prove that the TRS is (non-)confluent, we show (non-)confluence of the following modified system:

f(g(f(x381,g(b))),h(f(h(a),f(a,a)))) c
f(g(f(g(b),x383)),h(f(f(a,a),h(a)))) c
f(h(f(h(a),f(a,a))),g(f(g(b),x))) c
f(x,y) f(y,x)
g(g(a)) f(h(g(f(c,c))),f(f(g(c),a),g(f(a,a))))
f(h(f(f(a,a),h(a))),g(f(x,g(b)))) c
c f(a,h(b))
f(h(f(f(a,a),h(a))),g(f(g(b),x))) c
f(h(f(h(a),f(a,a))),g(f(x,g(b)))) c
f(g(f(x61,g(b))),h(f(f(a,a),h(a)))) c
f(g(f(g(b),x)),h(f(h(a),f(a,a)))) c
f(g(f(g(b),x383)),h(f(h(a),f(a,a)))) c
f(g(f(g(b),x381)),h(f(h(a),f(a,a)))) c
f(g(f(g(b),x1222)),h(f(h(a),f(a,a)))) c

All redundant rules that were added or removed can be simulated in 2 steps .

1.1.1.1.1.1.1 Strongly closed

Confluence is proven since the TRS is strongly closed. The joins can be performed within 7 step(s).

Tool configuration

csi