active
from
X
mark
cons
X
from
s
X
active
length
nil
mark
0
active
length
cons
X
Y
mark
s
length1
Y
active
length1
X
mark
length
X
active
from
X
from
active
X
active
cons
X1
X2
cons
active
X1
X2
active
s
X
s
active
X
from
mark
X
mark
from
X
cons
mark
X1
X2
mark
cons
X1
X2
s
mark
X
mark
s
X
proper
from
X
from
proper
X
proper
cons
X1
X2
cons
proper
X1
proper
X2
proper
s
X
s
proper
X
proper
length
X
length
proper
X
proper
nil
ok
nil
proper
0
ok
0
proper
length1
X
length1
proper
X
from
ok
X
ok
from
X
cons
ok
X1
ok
X2
ok
cons
X1
X2
s
ok
X
ok
s
X
length
ok
X
ok
length
X
length1
ok
X
ok
length1
X
top
mark
X
top
proper
X
top
ok
X
top
active
X
active
1
from
1
mark
1
cons
2
s
1
length
1
nil
0
0
0
length1
1
proper
1
ok
1
top
1
FULL
./TRS/TRCSR/Ex14_AEGL02_C.trs