font-style: italic;">collapsing
</span>type language morphism
from the expressions of expressions type language to the expressions
type language. The triple of operators (<span
 style="font-style: italic;">expressions</span>, <span
 style="font-style: italic;">embedding</span>,
<span style="font-style: italic;">collapsing</span>) has nice monoidal
properties (identity, associativity, etc.). Associated with this triple
is the derived
context of type language interpretations. Intuitively, a type language
<spa