YES Confluence Proof

Confluence Proof

by csi

Input

The rewrite relation of the following TRS is considered.

+(x,0) x
+(x,s(y)) s(+(x,y))
d(0) 0
d(s(x)) s(s(d(x)))
f(0) 0
f(s(x)) +(+(s(x),s(x)),s(x))
f(g(0)) +(+(g(0),g(0)),g(0))
g(x) s(d(x))

Proof

1 Decreasing Diagrams

1.1 Relative Termination Proof

The duplicating rules (R) terminate relative to the other rules (S).

1.1.1 Rule Removal

Using the recursive path order with the following precedence and status
prec(g) = 3 stat(g) = lex
prec(f) = 3 stat(f) = lex
prec(d) = 1 stat(d) = lex
prec(s) = 0 stat(s) = lex
prec(+) = 2 stat(+) = lex
prec(0) = 0 stat(0) = lex
all rules of R could be removed. Moreover, all rules of S could be removed.

1.1.1.1 R is empty

There are no rules in the TRS R. Hence, R/S is relative terminating.

1.2 Rule Labeling

Confluence is proven, because all critical peaks can be joined decreasingly using the following rule labeling function (rules that are not shown have label 0). All critical pairs are joinable:

Tool configuration

csi