owl-tools#55

[jsjuni]

Fixes owl-tools#55

[jsjuni]

I had to make a small logic modification. The siblingMap() method was used only to generate disjointness axioms, and consequently included only parent classes with more than one child. In the enhanced version it's also used to generate subclass axioms and therefore needs to include that case. I renamed it to childrenMap and moved the logic for checking more than one child to generateClosureAxioms().

[melaasar]

LGTM