equal
deleted
inserted
replaced
277 fun filter_goal could ths i = filter_thms could (999, getgoal i, ths); |
277 fun filter_goal could ths i = filter_thms could (999, getgoal i, ths); |
278 |
278 |
279 (*For inspecting earlier levels of the backward proof*) |
279 (*For inspecting earlier levels of the backward proof*) |
280 fun chop_level n (pair,pairs) = |
280 fun chop_level n (pair,pairs) = |
281 let val level = length pairs |
281 let val level = length pairs |
282 in if 0<=n andalso n<= level |
282 in if n<0 andalso ~n <= level |
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283 then drop (~n, pair::pairs) |
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284 else if 0<=n andalso n<= level |
283 then drop (level - n, pair::pairs) |
285 then drop (level - n, pair::pairs) |
284 else error ("Level number must lie between 0 and " ^ |
286 else error ("Level number must lie between 0 and " ^ |
285 string_of_int level) |
287 string_of_int level) |
286 end; |
288 end; |
287 |
289 |