Def pq == if p q else false fi

is mentioned by

Thm* L:T List, P:(T). (xL.P(x))  reduce(x,y. P(x)y;true;L)	[l_all_reduce]
Def count(x < y in L | P(x;y)) Def == sum(if (i<j)P(L[i];L[j]) 1 else 0 fi | i < ||L||; j < ||L||)	[count_pairs]

In prior sections: bool 1 mb list 1

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