# Observable

An observable is either a molecule, species or simply a pattern. Observables correspond to quantities that would be measured in typical biological experiments. Examples include observed phosphorylation of a protein and the amount of a protein that is co-complexed with another protein.

By design, and by virtue of allowing patterns, observables may delibrately not be fully specified: components of defined molecules may be missing, state labels of multi-state components may be absent indicating that they can take on any value, edge names may be given with wildcards to specify various connectivity, and the molecules in a complex need not be connected. This incompleteness of specification allows patterns to match range of species. The values of observables over a simulation generated timecourse are written to output files.