leq
0
x
tt
leq
s
x
0
ff
leq
s
x
s
y
leq
x
y
split
nil
app
nil
nil
split
cons
x
nil
app
cons
x
nil
nil
split
cons
x
cons
y
xs
split1
x
y
split
xs
split1
x
y
app
xs
ys
app
cons
x
xs
cons
y
ys
merge
[]
xs
xs
merge
xs
[]
xs
merge
cons
x
xs
cons
y
ys
ifmerge
leq
x
y
x
y
xs
ys
ifmerge
tt
x
y
xs
ys
cons
x
merge
xs
cons
y
ys
ifmerge
ff
x
y
xs
ys
cons
y
merge
cons
x
xs
ys
mergesort
xs
mergesort1
split
xs
mergesort1
app
xs
ys
merge
mergesort
xs
mergesort
ys
leq
2
0
0
tt
0
s
1
ff
0
split
1
nil
0
app
2
cons
2
split1
3
merge
2
[]
0
ifmerge
5
mergesort
1
mergesort1
1
FULL
./TCT_09/mergesort.trs