Description: The extended sum of a singleton is the term. (Contributed by Thierry Arnoux, 2-Jan-2017) (Revised by Thierry Arnoux, 2-May-2020)
Ref | Expression | ||
---|---|---|---|
Hypotheses | esumsnf.0 | |
|
esumsnf.1 | |
||
esumsnf.2 | |
||
esumsnf.3 | |
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Assertion | esumsnf | |