ap
ap
map
f
xs
ap
ap
ap
if
ap
isEmpty
xs
f
xs
ap
ap
ap
if
true
f
xs
null
ap
ap
ap
if
null
f
xs
ap
ap
cons
ap
f
ap
last
xs
ap
ap
if2
f
xs
ap
ap
if2
f
xs
ap
ap
map
f
ap
dropLast
xs
ap
isEmpty
null
true
ap
isEmpty
ap
ap
cons
x
xs
null
ap
last
ap
ap
cons
x
null
x
ap
last
ap
ap
cons
x
ap
ap
cons
y
ys
ap
last
ap
ap
cons
y
ys
ap
dropLast
ap
ap
cons
x
null
null
ap
dropLast
ap
ap
cons
x
ap
ap
cons
y
ys
ap
ap
cons
x
ap
dropLast
ap
ap
cons
y
ys
2.2
ap
dropLast
ap
ap
cons
x
ap
ap
cons
y
ys
ap
dropLast
ap
ap
cons
y
ys
ap
ap
ap
if
null
f
xs
ap
last
xs
ap
last
ap
ap
cons
x
ap
ap
cons
y
ys
ap
last
ap
ap
cons
y
ys
ap
ap
map
f
xs
ap
ap
ap
if
ap
isEmpty
xs
f
xs
ap
ap
map
f
xs
ap
if
ap
isEmpty
xs
ap
ap
map
f
xs
ap
isEmpty
xs
ap
ap
if2
f
xs
ap
ap
map
f
ap
dropLast
xs
ap
ap
ap
if
null
f
xs
ap
ap
if2
f
xs
ap
ap
map
f
xs
ap
ap
if
ap
isEmpty
xs
f
ap
ap
ap
if
null
f
xs
ap
f
ap
last
xs
ap
ap
if2
f
xs
ap
dropLast
xs
ap
ap
ap
if
null
f
xs
ap
ap
cons
ap
f
ap
last
xs
ap
ap
if2
f
xs
ap
dropLast
ap
ap
cons
x
ap
ap
cons
y
ys
ap
ap
cons
x
ap
dropLast
ap
ap
cons
y
ys
ap
ap
ap
if
null
f
xs
ap
if2
f
ap
ap
if2
f
xs
ap
map
f
ap
ap
ap
if
null
f
xs
ap
cons
ap
f
ap
last
xs
true
ap
ap
if2
f
xs
ap
ap
map
f
ap
dropLast
xs
ap
ap
map
f
xs
ap
ap
ap
if
ap
isEmpty
xs
f
xs
ap
ap
ap
if
null
f
xs
ap
f
ap
last
xs
ap
ap
ap
if
null
f
xs
ap
ap
if2
f
xs
true
Failed!
NaTT
certifiable-1.6