Within trillionths of a second after the Big Bang, they have reasoned, the primordial explosion - many billions of degrees hot - must have created a universe that contained equal quantities of matter and antimatter.
The Big Bang occurred over a period of several minutes.
The Big Bang occurred and within a matter of trillionths of a second there were reactions.  The system was likely fooled by the association to time.
( z1 event :name ( z2 name :op "Big" :op "Bang" ) :duration ( z3 several :op ( z4 temporal-quantity :quant 1 :unit ( z5 minute ) ) ) )