29.3 IsBlist

IsBlist( obj )

IsBlist returns true if obj, which may be an object of arbitrary type, is a boolean list and false otherwise. A boolean list is a list that has no holes and contains only true and false.

    gap> IsBlist( [ true, true, false, false ] );
    true
    gap> IsBlist( [] );
    true
    gap> IsBlist( [false,,true] );
    false    # has holes
    gap> IsBlist( [1,1,0,0] );
    false    # contains not only boolean values
    gap> IsBlist( 17 );
    false    # is not even a list 

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