Function Repository Resource:

EquivalenceClasses

Compute the equivalence classes associated with a given set of elementwise identifications

Contributed by: Shuheng Li

ResourceFunction["EquivalenceClasses"][list,{{a₁,a₂},{b₁,b₂},…}]

partitions list into equivalence classes according to the relations a₁~a₂,b₁~b₂,….

Details

The minimal equivalence relation containing the relations a₁~a₂, b₁~b₂,… is assumed.

Equivalence classes of Range[1,5] under the relations 1~3 and 3~5:

In[1]:=

Out[1]=

If no relations are given, EquivalenceClasses returns the singleton elements of list:

In[2]:=

Out[2]=