There's an exception to every rule, including this one.
   Sifferent, for use by all, by Kenneth Udut. [1]sifferent
   Sifferent

                SIFFERENT: Definition and explanation

   Most things that are the same are really a little different and
   things that are quite different have at least some things in
   common, making them a little the same. Both the same and
   different. Either the same or different. It all depends on your
   perspective. If it's not entirely interchangable, its sifferent.
   As soon as you have an "if" or an "if and only if" or some kind
   of conditions or contexts or "in this case" - they belong in the
   sifferent category. When we're young, we're taught "same" vs
   "different". It's useful for many things, usually for
   counting/mathematics. If you treat things the same, you can
   group them together and treat them as if they are one thing.
   Apples. Bananas. But even when we are young, we see that things
   that are the same are also different. Different shapes,
   different sizes, different levels of ripeness or even "this one
   is on this side of the page, and this other one is on that side
   of the page. They look the same but they are in different
   places, so they're different AND the same." Typically that
   viewpoint is not rewarded. Same is same, different is different
   and there is no overlap - that's how we're taught. Strict,
   unyeilding categories of "Same and different" leads to
   stereotyping and prejudice and categorizing people as well as
   things. Higher minds figure it out even young; we're all
   different and also the same - that there are exceptions to every
   rule. Lesser minds believe the compartments "EITHER same OR
   different". It's necessary many times to treat things *as if*
   they are the same or *as if* they are different but they're both
   and neither. Everything that isn't exactly the same, is
   sifferent. No English word captures that. Until now.

Sifferent: An Original Idea by Kenneth Udut - July 28, 2014

  Use Sifferent freely. It describes things that are not strictly
  equivalent. Things that are strictly equivilant are entirely
  interchangable.

     [2]same_and_different   Same and Different Worksheet This
   worksheet from [3]Human System Dynamics is a very simple and
   powerful tool for resolving one of the most difficult things
   humans deal with: disagreements and misunderstandings between
   fellow humans. I looked through Mathematical Symbols that could
   indicate things that are both same and different, for an
   opposite to "strictly equivilent to". No single symbol captured
   them all. I could have used !=== but it doesn't capture the
   fundamental concept. Mathematics is beautiful and
   extraordinarily useful but it operates under a Closed World
   Assumption. Most systems of logic do as well, although not all.
   See Wikipedia for definition. Note: Even two things that appear
   to be identical in every which way - electrons are a wonderful
   example, are sifferent. Even when there is superimposition,
   there is still a distinction. Quantum superimposition is a
   fantastic example of sifferent that goes beyond human psychology
   straight into something that should not confuse us at all, but
   does. It behaves like a wave when unobserved and behaves like a
   particle observered. Sifferent. Alternate wording: Is it the
   same or different? Well, it depends. If they're not STRICTLY
   EQUIVALENT, they're sifferent: A concept that's only a paradox
   if you believe that the context you use (your perspective or the
   one of your chosen field) is the ONLY valid one. (CLOSED WORLD
   ASSUMPTION) There is more to come, including animations. This is
   just stage one. 7/28/2014 Kenneth Udut - I'm easy to find
   online. Contact me if you like.

References

   Visible links
   1. http://icopiedyou.com/wp-content/uploads/2016/02/sifferent.png
   2. http://icopiedyou.com/wp-content/uploads/2016/02/same_and_different.jpg
   3. http://wiki.hsdinstitute.org/same_and_different