## Slots on this relation:

**Documentation: **
The qualitative proportionality, Qprop-, also known as an indirect
influence in the qualitative process theory literature, states that
all things being equal ?x is proportional to ?y. If there are no
other influences on ?x, then (Qprop- ?x ?y) is equivalent
to (M- ?y ?x). Otherwise, it means that x = f(...,y,...) and the
partial of f w.r.t. y is less than zero.

**Arity: **2
**Domain: **Time-dependent-quantity
**Range: **Time-dependent-quantity