D = pruneDiff(C, n)
D = pruneDiff(C, n, M)
Completely prunes the n-th differential of the chain complex C by removing unit elements.
Computing the syzygy over a local ring using liftUp and pruneDiff:
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This is the process for finding the syzygy of FM:
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Now we prune the map h, which is the first map from the right:
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Scale each row with the common denominator of the corresponding column in FM:
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The syzygy of FM is:
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This method does not use the algorithms in the engine, hence it might be slow.
The object pruneDiff is a method function with options.