Mathematical operations (addition, subtraction, multiplication, division/proportion) are analyzed solely as paratactic structures with the functor
OPER (see below in Section 11.1, "Mathematical operations").
Intervals (temporal, spatial or other) are analyzed in two different ways: either as paratactic structures with the
OPER functor assigned to their root nodes, as well (see Section 11.2.3, "Intervals analyzed as a paratactic structure"), or by means of appropriate temporal and locative/directional functors (see Section 11.2.1, "Temporal intervals analyzed by means of temporal functors" and Section 11.2.2, "Spatial intervals analyzed by means of locative/directional functors").
Members of mathematical operations and intervals are called operands. Expressions conveying the meaning of the relevant operation or interval are called operators.