class ConstraintGroup
!!!188080.cpp!!!	addConstraint(inout constraintId : uint, in idx : uint, in c : SReal) : void
  equations.resize(equations.size()+1);
  ConstraintEquation &eq=equations.back();

  eq.idx = idx;
  eq.correction=c;

  eq.constraintId = constraintId;
  constraintId++;
