app
app
map
f
nil
nil
app
app
map
f
app
app
cons
x
xs
app
app
cons
app
f
x
app
app
map
f
xs
app
flatten
app
app
node
x
xs
app
app
cons
x
app
concat
app
app
map
flatten
xs
app
concat
nil
nil
app
concat
app
app
cons
x
xs
app
app
append
x
app
concat
xs
app
app
append
nil
xs
xs
app
app
append
app
app
cons
x
xs
ys
app
app
cons
x
app
app
append
xs
ys
app
2
map
0
nil
0
cons
0
flatten
0
node
0
concat
0
append
0
FULL
./TRS/higher-order/Bird/TreeFlatten.trs