Description: An unordered triple of ordered pairs restricted to all but one first components of the pairs is an unordered pair of ordered pairs. (Contributed by AV, 14-Mar-2020)
Ref | Expression | ||
---|---|---|---|
Hypotheses | tpres.t | |
|
tpres.b | |
||
tpres.c | |
||
tpres.e | |
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tpres.f | |
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tpres.1 | |
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tpres.2 | |
||
Assertion | tpres | |