| ⊦ flatten(val ++ initval(undone)) = flatten(val) ++ initval(undone) |
is_valuelist(val) ⊦ flatten(val ++ initval(undone)) = flatten(val) ++ initval(undone)
⊦ is_valuelist(val), flatten(val ++ initval(undone)) = flatten(val) ++ initval(undone)
[[CONCRETESIMPRULES : ()], [EXTRAFMAS : (is_valuelist(val))]]