Novel Euler/X diagnostics for inconsistent input alignments.
Two taxonomies together with 9 input articulations are shown in the TAP (taxonomy alignment problem) on the left. It is not clear what the “combined taxonomy” looks like. For this example, calling Euler/X’s “check-consistency” command yields “No” – the TAP is inconsistent, i.e., self-contradictory. Even for the trained expert it is difficult to locate the error. Euler/X can execute a “black-box inconsistency analysis”, trying various combinations of articulations to see which subsets of articulations are consistent. The resulting diagnosis lattice has 2^9 = 512 nodes, and is therefore hard to navigate. Euler/X can extract from the 512 combinations 9 maximal consistent sets (i.e., the purple combinations in the lower right cannot be extended with any of the missing articulations without rendering the alignment inconsistent), and 2 minimal inconsistent sets (i.e., the red subsets are already inconsistent, but removing any articulation will yield a consistent subset). This allows the user to effectively explore and understand the consistency/inconsistency landscape, leading to efficient repair actions.