Change DV_DURATION.sign to prefix "-" operation

Description

The sign attribute of DV_DURATION is incompatible with
the normal way of representing negation of a quantity. It is not
helpful in computations using durations. A prefix "-" operator
should be defined to enable normal arithmetic to be used with
DV_DURATIONs.

Status

Assignee

JeffJ

Reporter

JeffJ

Raised By

None

Priority

Trivial
Configure