Term Rewriting System R:
[Y, X]
minus(0, Y) -> 0
minus(s(X), s(Y)) -> minus(X, Y)
geq(X, 0) -> true
geq(0, s(Y)) -> false
geq(s(X), s(Y)) -> geq(X, Y)
div(0, s(Y)) -> 0
div(s(X), s(Y)) -> if(geq(X, Y), s(div(minus(X, Y), s(Y))), 0)
if(true, X, Y) -> X
if(false, X, Y) -> Y

Termination of R to be shown.



   R
Overlay and local confluence Check



The TRS is overlay and locally confluent (all critical pairs are trivially joinable).Hence, we can switch to innermost.


   R
OC
       →TRS2
Dependency Pair Analysis



R contains the following Dependency Pairs:

MINUS(s(X), s(Y)) -> MINUS(X, Y)
GEQ(s(X), s(Y)) -> GEQ(X, Y)
DIV(s(X), s(Y)) -> IF(geq(X, Y), s(div(minus(X, Y), s(Y))), 0)
DIV(s(X), s(Y)) -> GEQ(X, Y)
DIV(s(X), s(Y)) -> DIV(minus(X, Y), s(Y))
DIV(s(X), s(Y)) -> MINUS(X, Y)

Furthermore, R contains two SCCs.


   R
OC
       →TRS2
DPs
           →DP Problem 1
Usable Rules (Innermost)
           →DP Problem 2
UsableRules


Dependency Pair:

MINUS(s(X), s(Y)) -> MINUS(X, Y)


Rules:


minus(0, Y) -> 0
minus(s(X), s(Y)) -> minus(X, Y)
geq(X, 0) -> true
geq(0, s(Y)) -> false
geq(s(X), s(Y)) -> geq(X, Y)
div(0, s(Y)) -> 0
div(s(X), s(Y)) -> if(geq(X, Y), s(div(minus(X, Y), s(Y))), 0)
if(true, X, Y) -> X
if(false, X, Y) -> Y


Strategy:

innermost




As we are in the innermost case, we can delete all 9 non-usable-rules.


   R
OC
       →TRS2
DPs
           →DP Problem 1
UsableRules
             ...
               →DP Problem 3
Size-Change Principle
           →DP Problem 2
UsableRules


Dependency Pair:

MINUS(s(X), s(Y)) -> MINUS(X, Y)


Rule:

none


Strategy:

innermost




We number the DPs as follows:
  1. MINUS(s(X), s(Y)) -> MINUS(X, Y)
and get the following Size-Change Graph(s):
{1} , {1}
1>1
2>2

which lead(s) to this/these maximal multigraph(s):
{1} , {1}
1>1
2>2

DP: empty set
Oriented Rules: none

We used the order Homeomorphic Embedding Order with Non-Strict Precedence.
trivial

with Argument Filtering System:
s(x1) -> s(x1)

We obtain no new DP problems.


   R
OC
       →TRS2
DPs
           →DP Problem 1
UsableRules
           →DP Problem 2
Usable Rules (Innermost)


Dependency Pair:

GEQ(s(X), s(Y)) -> GEQ(X, Y)


Rules:


minus(0, Y) -> 0
minus(s(X), s(Y)) -> minus(X, Y)
geq(X, 0) -> true
geq(0, s(Y)) -> false
geq(s(X), s(Y)) -> geq(X, Y)
div(0, s(Y)) -> 0
div(s(X), s(Y)) -> if(geq(X, Y), s(div(minus(X, Y), s(Y))), 0)
if(true, X, Y) -> X
if(false, X, Y) -> Y


Strategy:

innermost




As we are in the innermost case, we can delete all 9 non-usable-rules.


   R
OC
       →TRS2
DPs
           →DP Problem 1
UsableRules
           →DP Problem 2
UsableRules
             ...
               →DP Problem 4
Size-Change Principle


Dependency Pair:

GEQ(s(X), s(Y)) -> GEQ(X, Y)


Rule:

none


Strategy:

innermost




We number the DPs as follows:
  1. GEQ(s(X), s(Y)) -> GEQ(X, Y)
and get the following Size-Change Graph(s):
{1} , {1}
1>1
2>2

which lead(s) to this/these maximal multigraph(s):
{1} , {1}
1>1
2>2

DP: empty set
Oriented Rules: none

We used the order Homeomorphic Embedding Order with Non-Strict Precedence.
trivial

with Argument Filtering System:
s(x1) -> s(x1)

We obtain no new DP problems.

Termination of R successfully shown.
Duration:
0:00 minutes