app
nil
xs
xs
app
cons
x
xs
ys
cons
x
app
xs
ys
foldl
F
xs
nil
xs
foldl
F
xs
cons
y
ys
foldl
F
F
xs
y
ys
iconsc
xs
list
x
nat
cons
x
xs
reverse
xs
foldl
iconsc
nil
xs
reverse1
xs
foldl
lx
list
x
nat
app
cons
x
nil
lx
nil
xs
x
nat
y
nat
F
list
nat
list
xs
list
ys
list
app
list
list
list
nil
list
cons
nat
list
list
foldl
list
nat
list
list
list
list
reverse
list
list
reverse1
list
list
iconsc
list
nat
list
FULL
.