active
first
0
X
mark
nil
active
first
s
X
cons
Y
Z
mark
cons
Y
first
X
Z
active
from
X
mark
cons
X
from
s
X
active
first
X1
X2
first
active
X1
X2
active
first
X1
X2
first
X1
active
X2
active
s
X
s
active
X
active
cons
X1
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cons
active
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from
X
from
active
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X1
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cons
X1
X2
from
mark
X
mark
from
X
proper
first
X1
X2
first
proper
X1
proper
X2
proper
0
ok
0
proper
nil
ok
nil
proper
s
X
s
proper
X
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X1
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cons
proper
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proper
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from
X
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proper
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ok
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ok
X
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X
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mark
X
top
proper
X
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ok
X
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active
X
active
1
first
2
0
0
mark
1
nil
0
s
1
cons
2
from
1
proper
1
ok
1
top
1
INNERMOST
./TRS/TRCSR/inn/Ex6_Luc98_C.trs