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posetJoin -- returns the join of two elements

Synopsis

Description

This function returns the least element that is greater than both a and b in P.
i1 : P = poset ({a,b,c,d,e,f}, {(a,d),(d,f),(b,d),(b,e),(c,e),(e,f)});
i2 : posetJoin (P, a,b)

o2 = {d}

o2 : List

Caveat

This function returns an error if the join does not exist. To check if the join exists use joinExists.

See also

Ways to use posetJoin :