Definition 6.130.
A prelogos is just a pretopos. A morphism of prelogoi from \(S\) to \(T\) is a functor \(f^*\colon S \to T\) which preserves finite limits, finite coproducts, and colimits of groupoids. This defines a category \(\Logos^{\pre}\) of prelogoi. The category of pretopoi is defined as \(\Topos^{\pre} := (\Logos^{\pre})\catop\).