146f5ddd1ac881fbebdeff83c0be0322bf7e1d74,dit/math/sigmaalgebra.py,,is_sigma_algebra__brute,#Any#Any#,161

Before Change

    Its time complexity is O( len(F)**2 ).

    
    if X is None:
        X = set([])
        for cet in F:
            X.update(cet)
    X = frozenset(X)

    for subset1 in F:
        if X.difference(subset1) not in F:

After Change

    // This works because its not necessary to test countable unions if the
    // base set X is finite.  One need only consider pairwise unions.
    if X is None:
        X = frozenset().union(*F)
    else:
        X = frozenset(X)

    for subset1 in F:

Instances