Interpretation of species' constant and boundaryCondition attributes.

constant value	boundaryCondition value	Can have assignment or rate rule?	Can be reactant or product?	Species' quantity can be changed by
true	true	no	yes	(never changes)
false	true	yes	yes	rules and events
true	false	no	no	(never changes)
false	false	yes	yes	reactions or rules (but not both at the same time), and events