R
↳Dependency Pair Analysis
DEL(.(x, .(y, z))) -> F(=(x, y), x, y, z)
DEL(.(x, .(y, z))) -> ='(x, y)
F(true, x, y, z) -> DEL(.(y, z))
F(false, x, y, z) -> DEL(.(y, z))
='(.(x, y), .(u, v)) -> ='(x, u)
='(.(x, y), .(u, v)) -> ='(y, v)
R
↳DPs
→DP Problem 1
↳Narrowing Transformation
F(false, x, y, z) -> DEL(.(y, z))
F(true, x, y, z) -> DEL(.(y, z))
DEL(.(x, .(y, z))) -> F(=(x, y), x, y, z)
del(.(x, .(y, z))) -> f(=(x, y), x, y, z)
f(true, x, y, z) -> del(.(y, z))
f(false, x, y, z) -> .(x, del(.(y, z)))
=(nil, nil) -> true
=(.(x, y), nil) -> false
=(nil, .(y, z)) -> false
=(.(x, y), .(u, v)) -> and(=(x, u), =(y, v))
innermost
four new Dependency Pairs are created:
DEL(.(x, .(y, z))) -> F(=(x, y), x, y, z)
DEL(.(nil, .(nil, z))) -> F(true, nil, nil, z)
DEL(.(.(x'', y''), .(nil, z))) -> F(false, .(x'', y''), nil, z)
DEL(.(nil, .(.(y'', z''), z))) -> F(false, nil, .(y'', z''), z)
DEL(.(.(x'', y''), .(.(u, v), z))) -> F(and(=(x'', u), =(y'', v)), .(x'', y''), .(u, v), z)
R
↳DPs
→DP Problem 1
↳Nar
→DP Problem 2
↳Instantiation Transformation
DEL(.(nil, .(.(y'', z''), z))) -> F(false, nil, .(y'', z''), z)
DEL(.(.(x'', y''), .(nil, z))) -> F(false, .(x'', y''), nil, z)
F(true, x, y, z) -> DEL(.(y, z))
DEL(.(nil, .(nil, z))) -> F(true, nil, nil, z)
F(false, x, y, z) -> DEL(.(y, z))
del(.(x, .(y, z))) -> f(=(x, y), x, y, z)
f(true, x, y, z) -> del(.(y, z))
f(false, x, y, z) -> .(x, del(.(y, z)))
=(nil, nil) -> true
=(.(x, y), nil) -> false
=(nil, .(y, z)) -> false
=(.(x, y), .(u, v)) -> and(=(x, u), =(y, v))
innermost
one new Dependency Pair is created:
F(true, x, y, z) -> DEL(.(y, z))
F(true, nil, nil, z'') -> DEL(.(nil, z''))
R
↳DPs
→DP Problem 1
↳Nar
→DP Problem 2
↳Inst
...
→DP Problem 3
↳Instantiation Transformation
DEL(.(.(x'', y''), .(nil, z))) -> F(false, .(x'', y''), nil, z)
F(true, nil, nil, z'') -> DEL(.(nil, z''))
DEL(.(nil, .(nil, z))) -> F(true, nil, nil, z)
F(false, x, y, z) -> DEL(.(y, z))
DEL(.(nil, .(.(y'', z''), z))) -> F(false, nil, .(y'', z''), z)
del(.(x, .(y, z))) -> f(=(x, y), x, y, z)
f(true, x, y, z) -> del(.(y, z))
f(false, x, y, z) -> .(x, del(.(y, z)))
=(nil, nil) -> true
=(.(x, y), nil) -> false
=(nil, .(y, z)) -> false
=(.(x, y), .(u, v)) -> and(=(x, u), =(y, v))
innermost
two new Dependency Pairs are created:
F(false, x, y, z) -> DEL(.(y, z))
F(false, .(x'''', y''''), nil, z'') -> DEL(.(nil, z''))
F(false, nil, .(y'''', z''''), z'') -> DEL(.(.(y'''', z''''), z''))
R
↳DPs
→DP Problem 1
↳Nar
→DP Problem 2
↳Inst
...
→DP Problem 4
↳Forward Instantiation Transformation
F(false, nil, .(y'''', z''''), z'') -> DEL(.(.(y'''', z''''), z''))
DEL(.(nil, .(.(y'', z''), z))) -> F(false, nil, .(y'', z''), z)
F(true, nil, nil, z'') -> DEL(.(nil, z''))
DEL(.(nil, .(nil, z))) -> F(true, nil, nil, z)
F(false, .(x'''', y''''), nil, z'') -> DEL(.(nil, z''))
DEL(.(.(x'', y''), .(nil, z))) -> F(false, .(x'', y''), nil, z)
del(.(x, .(y, z))) -> f(=(x, y), x, y, z)
f(true, x, y, z) -> del(.(y, z))
f(false, x, y, z) -> .(x, del(.(y, z)))
=(nil, nil) -> true
=(.(x, y), nil) -> false
=(nil, .(y, z)) -> false
=(.(x, y), .(u, v)) -> and(=(x, u), =(y, v))
innermost
two new Dependency Pairs are created:
F(true, nil, nil, z'') -> DEL(.(nil, z''))
F(true, nil, nil, .(nil, z''')) -> DEL(.(nil, .(nil, z''')))
F(true, nil, nil, .(.(y'''', z''''), z'0)) -> DEL(.(nil, .(.(y'''', z''''), z'0)))
R
↳DPs
→DP Problem 1
↳Nar
→DP Problem 2
↳Inst
...
→DP Problem 5
↳Forward Instantiation Transformation
DEL(.(nil, .(.(y'', z''), z))) -> F(false, nil, .(y'', z''), z)
F(true, nil, nil, .(.(y'''', z''''), z'0)) -> DEL(.(nil, .(.(y'''', z''''), z'0)))
F(true, nil, nil, .(nil, z''')) -> DEL(.(nil, .(nil, z''')))
DEL(.(nil, .(nil, z))) -> F(true, nil, nil, z)
F(false, .(x'''', y''''), nil, z'') -> DEL(.(nil, z''))
DEL(.(.(x'', y''), .(nil, z))) -> F(false, .(x'', y''), nil, z)
F(false, nil, .(y'''', z''''), z'') -> DEL(.(.(y'''', z''''), z''))
del(.(x, .(y, z))) -> f(=(x, y), x, y, z)
f(true, x, y, z) -> del(.(y, z))
f(false, x, y, z) -> .(x, del(.(y, z)))
=(nil, nil) -> true
=(.(x, y), nil) -> false
=(nil, .(y, z)) -> false
=(.(x, y), .(u, v)) -> and(=(x, u), =(y, v))
innermost
two new Dependency Pairs are created:
DEL(.(nil, .(nil, z))) -> F(true, nil, nil, z)
DEL(.(nil, .(nil, .(nil, z''''')))) -> F(true, nil, nil, .(nil, z'''''))
DEL(.(nil, .(nil, .(.(y'''''', z''''''), z'0'')))) -> F(true, nil, nil, .(.(y'''''', z''''''), z'0''))
R
↳DPs
→DP Problem 1
↳Nar
→DP Problem 2
↳Inst
...
→DP Problem 6
↳Forward Instantiation Transformation
F(true, nil, nil, .(.(y'''', z''''), z'0)) -> DEL(.(nil, .(.(y'''', z''''), z'0)))
DEL(.(nil, .(nil, .(.(y'''''', z''''''), z'0'')))) -> F(true, nil, nil, .(.(y'''''', z''''''), z'0''))
F(true, nil, nil, .(nil, z''')) -> DEL(.(nil, .(nil, z''')))
DEL(.(nil, .(nil, .(nil, z''''')))) -> F(true, nil, nil, .(nil, z'''''))
F(false, .(x'''', y''''), nil, z'') -> DEL(.(nil, z''))
DEL(.(.(x'', y''), .(nil, z))) -> F(false, .(x'', y''), nil, z)
F(false, nil, .(y'''', z''''), z'') -> DEL(.(.(y'''', z''''), z''))
DEL(.(nil, .(.(y'', z''), z))) -> F(false, nil, .(y'', z''), z)
del(.(x, .(y, z))) -> f(=(x, y), x, y, z)
f(true, x, y, z) -> del(.(y, z))
f(false, x, y, z) -> .(x, del(.(y, z)))
=(nil, nil) -> true
=(.(x, y), nil) -> false
=(nil, .(y, z)) -> false
=(.(x, y), .(u, v)) -> and(=(x, u), =(y, v))
innermost
three new Dependency Pairs are created:
F(false, .(x'''', y''''), nil, z'') -> DEL(.(nil, z''))
F(false, .(x'''', y''''), nil, .(.(y'''', z''''), z'0)) -> DEL(.(nil, .(.(y'''', z''''), z'0)))
F(false, .(x'''', y''''), nil, .(nil, .(nil, z'''''''))) -> DEL(.(nil, .(nil, .(nil, z'''''''))))
F(false, .(x'''', y''''), nil, .(nil, .(.(y'''''''', z''''''''), z'0''''))) -> DEL(.(nil, .(nil, .(.(y'''''''', z''''''''), z'0''''))))
R
↳DPs
→DP Problem 1
↳Nar
→DP Problem 2
↳Inst
...
→DP Problem 7
↳Forward Instantiation Transformation
F(false, .(x'''', y''''), nil, .(nil, .(.(y'''''''', z''''''''), z'0''''))) -> DEL(.(nil, .(nil, .(.(y'''''''', z''''''''), z'0''''))))
DEL(.(nil, .(nil, .(.(y'''''', z''''''), z'0'')))) -> F(true, nil, nil, .(.(y'''''', z''''''), z'0''))
F(true, nil, nil, .(nil, z''')) -> DEL(.(nil, .(nil, z''')))
DEL(.(nil, .(nil, .(nil, z''''')))) -> F(true, nil, nil, .(nil, z'''''))
F(false, .(x'''', y''''), nil, .(nil, .(nil, z'''''''))) -> DEL(.(nil, .(nil, .(nil, z'''''''))))
F(false, .(x'''', y''''), nil, .(.(y'''', z''''), z'0)) -> DEL(.(nil, .(.(y'''', z''''), z'0)))
DEL(.(.(x'', y''), .(nil, z))) -> F(false, .(x'', y''), nil, z)
F(false, nil, .(y'''', z''''), z'') -> DEL(.(.(y'''', z''''), z''))
DEL(.(nil, .(.(y'', z''), z))) -> F(false, nil, .(y'', z''), z)
F(true, nil, nil, .(.(y'''', z''''), z'0)) -> DEL(.(nil, .(.(y'''', z''''), z'0)))
del(.(x, .(y, z))) -> f(=(x, y), x, y, z)
f(true, x, y, z) -> del(.(y, z))
f(false, x, y, z) -> .(x, del(.(y, z)))
=(nil, nil) -> true
=(.(x, y), nil) -> false
=(nil, .(y, z)) -> false
=(.(x, y), .(u, v)) -> and(=(x, u), =(y, v))
innermost
three new Dependency Pairs are created:
DEL(.(.(x'', y''), .(nil, z))) -> F(false, .(x'', y''), nil, z)
DEL(.(.(x''', y'''), .(nil, .(.(y''''''', z''''''), z'0'')))) -> F(false, .(x''', y'''), nil, .(.(y''''''', z''''''), z'0''))
DEL(.(.(x''', y'''), .(nil, .(nil, .(nil, z'''''''''))))) -> F(false, .(x''', y'''), nil, .(nil, .(nil, z''''''''')))
DEL(.(.(x''', y'''), .(nil, .(nil, .(.(y'''''''''', z''''''''''), z'0''''''))))) -> F(false, .(x''', y'''), nil, .(nil, .(.(y'''''''''', z''''''''''), z'0'''''')))
R
↳DPs
→DP Problem 1
↳Nar
→DP Problem 2
↳Inst
...
→DP Problem 8
↳Forward Instantiation Transformation
DEL(.(.(x''', y'''), .(nil, .(nil, .(.(y'''''''''', z''''''''''), z'0''''''))))) -> F(false, .(x''', y'''), nil, .(nil, .(.(y'''''''''', z''''''''''), z'0'''''')))
F(true, nil, nil, .(nil, z''')) -> DEL(.(nil, .(nil, z''')))
DEL(.(nil, .(nil, .(nil, z''''')))) -> F(true, nil, nil, .(nil, z'''''))
F(false, .(x'''', y''''), nil, .(nil, .(nil, z'''''''))) -> DEL(.(nil, .(nil, .(nil, z'''''''))))
DEL(.(.(x''', y'''), .(nil, .(nil, .(nil, z'''''''''))))) -> F(false, .(x''', y'''), nil, .(nil, .(nil, z''''''''')))
F(false, .(x'''', y''''), nil, .(.(y'''', z''''), z'0)) -> DEL(.(nil, .(.(y'''', z''''), z'0)))
DEL(.(.(x''', y'''), .(nil, .(.(y''''''', z''''''), z'0'')))) -> F(false, .(x''', y'''), nil, .(.(y''''''', z''''''), z'0''))
F(false, nil, .(y'''', z''''), z'') -> DEL(.(.(y'''', z''''), z''))
DEL(.(nil, .(.(y'', z''), z))) -> F(false, nil, .(y'', z''), z)
F(true, nil, nil, .(.(y'''', z''''), z'0)) -> DEL(.(nil, .(.(y'''', z''''), z'0)))
DEL(.(nil, .(nil, .(.(y'''''', z''''''), z'0'')))) -> F(true, nil, nil, .(.(y'''''', z''''''), z'0''))
F(false, .(x'''', y''''), nil, .(nil, .(.(y'''''''', z''''''''), z'0''''))) -> DEL(.(nil, .(nil, .(.(y'''''''', z''''''''), z'0''''))))
del(.(x, .(y, z))) -> f(=(x, y), x, y, z)
f(true, x, y, z) -> del(.(y, z))
f(false, x, y, z) -> .(x, del(.(y, z)))
=(nil, nil) -> true
=(.(x, y), nil) -> false
=(nil, .(y, z)) -> false
=(.(x, y), .(u, v)) -> and(=(x, u), =(y, v))
innermost
three new Dependency Pairs are created:
F(false, nil, .(y'''', z''''), z'') -> DEL(.(.(y'''', z''''), z''))
F(false, nil, .(y'''''', z'''''), .(nil, .(.(y''''''''', z''''''''), z'0''''))) -> DEL(.(.(y'''''', z'''''), .(nil, .(.(y''''''''', z''''''''), z'0''''))))
F(false, nil, .(y'''''', z'''''), .(nil, .(nil, .(nil, z''''''''''')))) -> DEL(.(.(y'''''', z'''''), .(nil, .(nil, .(nil, z''''''''''')))))
F(false, nil, .(y'''''', z'''''), .(nil, .(nil, .(.(y'''''''''''', z''''''''''''), z'0'''''''')))) -> DEL(.(.(y'''''', z'''''), .(nil, .(nil, .(.(y'''''''''''', z''''''''''''), z'0'''''''')))))
R
↳DPs
→DP Problem 1
↳Nar
→DP Problem 2
↳Inst
...
→DP Problem 9
↳Forward Instantiation Transformation
F(false, nil, .(y'''''', z'''''), .(nil, .(nil, .(.(y'''''''''''', z''''''''''''), z'0'''''''')))) -> DEL(.(.(y'''''', z'''''), .(nil, .(nil, .(.(y'''''''''''', z''''''''''''), z'0'''''''')))))
F(true, nil, nil, .(nil, z''')) -> DEL(.(nil, .(nil, z''')))
DEL(.(nil, .(nil, .(nil, z''''')))) -> F(true, nil, nil, .(nil, z'''''))
F(false, .(x'''', y''''), nil, .(nil, .(nil, z'''''''))) -> DEL(.(nil, .(nil, .(nil, z'''''''))))
DEL(.(.(x''', y'''), .(nil, .(nil, .(nil, z'''''''''))))) -> F(false, .(x''', y'''), nil, .(nil, .(nil, z''''''''')))
F(false, nil, .(y'''''', z'''''), .(nil, .(nil, .(nil, z''''''''''')))) -> DEL(.(.(y'''''', z'''''), .(nil, .(nil, .(nil, z''''''''''')))))
F(false, .(x'''', y''''), nil, .(.(y'''', z''''), z'0)) -> DEL(.(nil, .(.(y'''', z''''), z'0)))
DEL(.(.(x''', y'''), .(nil, .(.(y''''''', z''''''), z'0'')))) -> F(false, .(x''', y'''), nil, .(.(y''''''', z''''''), z'0''))
F(false, nil, .(y'''''', z'''''), .(nil, .(.(y''''''''', z''''''''), z'0''''))) -> DEL(.(.(y'''''', z'''''), .(nil, .(.(y''''''''', z''''''''), z'0''''))))
DEL(.(nil, .(.(y'', z''), z))) -> F(false, nil, .(y'', z''), z)
F(true, nil, nil, .(.(y'''', z''''), z'0)) -> DEL(.(nil, .(.(y'''', z''''), z'0)))
DEL(.(nil, .(nil, .(.(y'''''', z''''''), z'0'')))) -> F(true, nil, nil, .(.(y'''''', z''''''), z'0''))
F(false, .(x'''', y''''), nil, .(nil, .(.(y'''''''', z''''''''), z'0''''))) -> DEL(.(nil, .(nil, .(.(y'''''''', z''''''''), z'0''''))))
DEL(.(.(x''', y'''), .(nil, .(nil, .(.(y'''''''''', z''''''''''), z'0''''''))))) -> F(false, .(x''', y'''), nil, .(nil, .(.(y'''''''''', z''''''''''), z'0'''''')))
del(.(x, .(y, z))) -> f(=(x, y), x, y, z)
f(true, x, y, z) -> del(.(y, z))
f(false, x, y, z) -> .(x, del(.(y, z)))
=(nil, nil) -> true
=(.(x, y), nil) -> false
=(nil, .(y, z)) -> false
=(.(x, y), .(u, v)) -> and(=(x, u), =(y, v))
innermost
three new Dependency Pairs are created:
DEL(.(nil, .(.(y'', z''), z))) -> F(false, nil, .(y'', z''), z)
DEL(.(nil, .(.(y''', z'''), .(nil, .(.(y''''''''''', z''''''''''), z'0''''''))))) -> F(false, nil, .(y''', z'''), .(nil, .(.(y''''''''''', z''''''''''), z'0'''''')))
DEL(.(nil, .(.(y''', z'''), .(nil, .(nil, .(nil, z''''''''''''')))))) -> F(false, nil, .(y''', z'''), .(nil, .(nil, .(nil, z'''''''''''''))))
DEL(.(nil, .(.(y''', z'''), .(nil, .(nil, .(.(y'''''''''''''', z''''''''''''''), z'0'''''''''')))))) -> F(false, nil, .(y''', z'''), .(nil, .(nil, .(.(y'''''''''''''', z''''''''''''''), z'0''''''''''))))
R
↳DPs
→DP Problem 1
↳Nar
→DP Problem 2
↳Inst
...
→DP Problem 10
↳Argument Filtering and Ordering
DEL(.(nil, .(.(y''', z'''), .(nil, .(nil, .(.(y'''''''''''''', z''''''''''''''), z'0'''''''''')))))) -> F(false, nil, .(y''', z'''), .(nil, .(nil, .(.(y'''''''''''''', z''''''''''''''), z'0''''''''''))))
F(true, nil, nil, .(nil, z''')) -> DEL(.(nil, .(nil, z''')))
DEL(.(nil, .(nil, .(nil, z''''')))) -> F(true, nil, nil, .(nil, z'''''))
F(false, .(x'''', y''''), nil, .(nil, .(nil, z'''''''))) -> DEL(.(nil, .(nil, .(nil, z'''''''))))
DEL(.(.(x''', y'''), .(nil, .(nil, .(nil, z'''''''''))))) -> F(false, .(x''', y'''), nil, .(nil, .(nil, z''''''''')))
F(false, nil, .(y'''''', z'''''), .(nil, .(nil, .(nil, z''''''''''')))) -> DEL(.(.(y'''''', z'''''), .(nil, .(nil, .(nil, z''''''''''')))))
DEL(.(nil, .(.(y''', z'''), .(nil, .(nil, .(nil, z''''''''''''')))))) -> F(false, nil, .(y''', z'''), .(nil, .(nil, .(nil, z'''''''''''''))))
F(false, .(x'''', y''''), nil, .(.(y'''', z''''), z'0)) -> DEL(.(nil, .(.(y'''', z''''), z'0)))
DEL(.(.(x''', y'''), .(nil, .(.(y''''''', z''''''), z'0'')))) -> F(false, .(x''', y'''), nil, .(.(y''''''', z''''''), z'0''))
F(false, nil, .(y'''''', z'''''), .(nil, .(.(y''''''''', z''''''''), z'0''''))) -> DEL(.(.(y'''''', z'''''), .(nil, .(.(y''''''''', z''''''''), z'0''''))))
DEL(.(nil, .(.(y''', z'''), .(nil, .(.(y''''''''''', z''''''''''), z'0''''''))))) -> F(false, nil, .(y''', z'''), .(nil, .(.(y''''''''''', z''''''''''), z'0'''''')))
F(true, nil, nil, .(.(y'''', z''''), z'0)) -> DEL(.(nil, .(.(y'''', z''''), z'0)))
DEL(.(nil, .(nil, .(.(y'''''', z''''''), z'0'')))) -> F(true, nil, nil, .(.(y'''''', z''''''), z'0''))
F(false, .(x'''', y''''), nil, .(nil, .(.(y'''''''', z''''''''), z'0''''))) -> DEL(.(nil, .(nil, .(.(y'''''''', z''''''''), z'0''''))))
DEL(.(.(x''', y'''), .(nil, .(nil, .(.(y'''''''''', z''''''''''), z'0''''''))))) -> F(false, .(x''', y'''), nil, .(nil, .(.(y'''''''''', z''''''''''), z'0'''''')))
F(false, nil, .(y'''''', z'''''), .(nil, .(nil, .(.(y'''''''''''', z''''''''''''), z'0'''''''')))) -> DEL(.(.(y'''''', z'''''), .(nil, .(nil, .(.(y'''''''''''', z''''''''''''), z'0'''''''')))))
del(.(x, .(y, z))) -> f(=(x, y), x, y, z)
f(true, x, y, z) -> del(.(y, z))
f(false, x, y, z) -> .(x, del(.(y, z)))
=(nil, nil) -> true
=(.(x, y), nil) -> false
=(nil, .(y, z)) -> false
=(.(x, y), .(u, v)) -> and(=(x, u), =(y, v))
innermost
DEL(.(nil, .(nil, .(nil, z''''')))) -> F(true, nil, nil, .(nil, z'''''))
F(false, nil, .(y'''''', z'''''), .(nil, .(nil, .(nil, z''''''''''')))) -> DEL(.(.(y'''''', z'''''), .(nil, .(nil, .(nil, z''''''''''')))))
F(false, nil, .(y'''''', z'''''), .(nil, .(.(y''''''''', z''''''''), z'0''''))) -> DEL(.(.(y'''''', z'''''), .(nil, .(.(y''''''''', z''''''''), z'0''''))))
DEL(.(nil, .(nil, .(.(y'''''', z''''''), z'0'')))) -> F(true, nil, nil, .(.(y'''''', z''''''), z'0''))
F(false, nil, .(y'''''', z'''''), .(nil, .(nil, .(.(y'''''''''''', z''''''''''''), z'0'''''''')))) -> DEL(.(.(y'''''', z'''''), .(nil, .(nil, .(.(y'''''''''''', z''''''''''''), z'0'''''''')))))
POL(DEL(x1)) = 1 + x1 POL(false) = 1 POL(nil) = 1 POL(true) = 0 POL(.(x1, x2)) = x1 + x2 POL(F(x1, x2, x3, x4)) = x1 + x2 + x3 + x4
DEL(x1) -> DEL(x1)
F(x1, x2, x3, x4) -> F(x1, x2, x3, x4)
.(x1, x2) -> .(x1, x2)
R
↳DPs
→DP Problem 1
↳Nar
→DP Problem 2
↳Inst
...
→DP Problem 11
↳Dependency Graph
DEL(.(nil, .(.(y''', z'''), .(nil, .(nil, .(.(y'''''''''''''', z''''''''''''''), z'0'''''''''')))))) -> F(false, nil, .(y''', z'''), .(nil, .(nil, .(.(y'''''''''''''', z''''''''''''''), z'0''''''''''))))
F(true, nil, nil, .(nil, z''')) -> DEL(.(nil, .(nil, z''')))
F(false, .(x'''', y''''), nil, .(nil, .(nil, z'''''''))) -> DEL(.(nil, .(nil, .(nil, z'''''''))))
DEL(.(.(x''', y'''), .(nil, .(nil, .(nil, z'''''''''))))) -> F(false, .(x''', y'''), nil, .(nil, .(nil, z''''''''')))
DEL(.(nil, .(.(y''', z'''), .(nil, .(nil, .(nil, z''''''''''''')))))) -> F(false, nil, .(y''', z'''), .(nil, .(nil, .(nil, z'''''''''''''))))
F(false, .(x'''', y''''), nil, .(.(y'''', z''''), z'0)) -> DEL(.(nil, .(.(y'''', z''''), z'0)))
DEL(.(.(x''', y'''), .(nil, .(.(y''''''', z''''''), z'0'')))) -> F(false, .(x''', y'''), nil, .(.(y''''''', z''''''), z'0''))
DEL(.(nil, .(.(y''', z'''), .(nil, .(.(y''''''''''', z''''''''''), z'0''''''))))) -> F(false, nil, .(y''', z'''), .(nil, .(.(y''''''''''', z''''''''''), z'0'''''')))
F(true, nil, nil, .(.(y'''', z''''), z'0)) -> DEL(.(nil, .(.(y'''', z''''), z'0)))
F(false, .(x'''', y''''), nil, .(nil, .(.(y'''''''', z''''''''), z'0''''))) -> DEL(.(nil, .(nil, .(.(y'''''''', z''''''''), z'0''''))))
DEL(.(.(x''', y'''), .(nil, .(nil, .(.(y'''''''''', z''''''''''), z'0''''''))))) -> F(false, .(x''', y'''), nil, .(nil, .(.(y'''''''''', z''''''''''), z'0'''''')))
del(.(x, .(y, z))) -> f(=(x, y), x, y, z)
f(true, x, y, z) -> del(.(y, z))
f(false, x, y, z) -> .(x, del(.(y, z)))
=(nil, nil) -> true
=(.(x, y), nil) -> false
=(nil, .(y, z)) -> false
=(.(x, y), .(u, v)) -> and(=(x, u), =(y, v))
innermost