(0) Obligation:

Q restricted rewrite system:
The TRS R consists of the following rules:

if(if(x, y, z), u, v) → if(x, if(y, u, v), if(z, u, v))

Q is empty.

(1) DependencyPairsProof (EQUIVALENT transformation)

Using Dependency Pairs [AG00,LPAR04] we result in the following initial DP problem.

(2) Obligation:

Q DP problem:
The TRS P consists of the following rules:

IF(if(x, y, z), u, v) → IF(x, if(y, u, v), if(z, u, v))
IF(if(x, y, z), u, v) → IF(y, u, v)
IF(if(x, y, z), u, v) → IF(z, u, v)

The TRS R consists of the following rules:

if(if(x, y, z), u, v) → if(x, if(y, u, v), if(z, u, v))

Q is empty.
We have to consider all minimal (P,Q,R)-chains.

(3) QDPSizeChangeProof (EQUIVALENT transformation)

We used the following order and afs together with the size-change analysis [AAECC05] to show that there are no infinite chains for this DP problem.

Order:Homeomorphic Embedding Order

AFS:
if(x1, x2, x3)  =  if(x1, x2, x3)

From the DPs we obtained the following set of size-change graphs:

  • IF(if(x, y, z), u, v) → IF(x, if(y, u, v), if(z, u, v)) (allowed arguments on rhs = {1})
    The graph contains the following edges 1 > 1

  • IF(if(x, y, z), u, v) → IF(y, u, v) (allowed arguments on rhs = {1, 2, 3})
    The graph contains the following edges 1 > 1, 2 >= 2, 3 >= 3

  • IF(if(x, y, z), u, v) → IF(z, u, v) (allowed arguments on rhs = {1, 2, 3})
    The graph contains the following edges 1 > 1, 2 >= 2, 3 >= 3

We oriented the following set of usable rules [AAECC05,FROCOS05]. none

(4) TRUE