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IsFactorClosed

test whether a list of PPs is factor closed

Syntax
IsFactorClosed(L: LIST of power products): BOOL

Description
A set of power products is factor closed iff it contains every factor of every one of its elements. This function checks whether the given set is factor closed (also known as "order-ideal"). It is an error if the list L is empty.

Example
/**/  use P ::= QQ[x,y,z];
/**/  IsFactorClosed([1, x, x^2]);
true
/**/  IsFactorClosed([one(P), y^2]);
false

See Also