9VARIABLES: expand - CYANA variable

Initial value: 1

This variable controls the automatic, internal expansion of distance
restraints that involve pseudoatoms into ambiguous distance restraints
with the corresponding hydrogen atoms. If the variable has the value 1,
the expansions will take place, if it has the value 0, no expansions
will be made and distance restraints involving pseudo atoms will be
used as they are.

For instance, if expand = 1, an input restraint between HA and QB of
Ala will effectively be interpreted as an ambiguous distance restraint
with the three assignments HA-HB1, HA-HB2, and HA-HB3, and it is the
r^-6 sum of these three distances that will be checked against the
upper distance bound. Alternatively, if expand = 0, it is the single
distance HA-QB that will be checked against the upper distance bound.
