Macaulay2 » Documentation
Packages » Posets :: areIsomorphic
next | previous | forward | backward | up | index | toc

areIsomorphic -- determines if two posets are isomorphic

Synopsis

Description

Two posets are isomorphic if there is a partial order preserving bijection between the ground sets of the posets which preserves the specified ground set partitions.

i1 : C = chain 5;
i2 : P = poset {{a,b},{b,c},{c,d},{d,e}};
i3 : areIsomorphic(C, P)

o3 = true

The product of $n$ chains of length $2$ is isomorphic to the boolean lattice on $n$ elements. These are also isomorphic to the divisor lattice on the product of $n$ distinct primes.

i4 : B = booleanLattice 4;
i5 : B == product(4, i -> chain 2)

o5 = true
i6 : B == divisorPoset (2*3*5*7)

o6 = true
i7 : B == divisorPoset (2^2*3*5)

o7 = false

See also

Ways to use areIsomorphic :

For the programmer

The object areIsomorphic is a method function.