let x be object ; TARSKI:def 3 ( not x in {<*2,3,7,42*>,<*2,3,8,24*>} or x in IncreasingSolutionsOfSumOfReciprocals 4 )
assume
x in {<*2,3,7,42*>,<*2,3,8,24*>}
; x in IncreasingSolutionsOfSumOfReciprocals 4
then
( x = <*2,3,7,42*> or x = <*2,3,8,24*> )
by TARSKI:def 2;
hence
x in IncreasingSolutionsOfSumOfReciprocals 4
by Th119, Th120; verum