realizes The process of 'histidine catabolism' (GO:0006548) realizes the function 'histidine ammonia lyase activity' (GO:0004397) (note: here 'activity' denotes a function and not a process). We leave open the possibility of defining in future the sub-relations directly_realizes (as bewteen a function and it's functioning) and indirectly_realizes. NOTE: there appears to be some consistency in usage as to whether processes or continuants realize OBO_REL:0000034 relationship has_function_part is_realization_of involves_execution_of Relation between a process and a function, where the unfolding of the process requires the execution of the function. Class level: P realizes F iff: given any p that instantiates P, there exists some f, t such that f instantiates F at t and p *realizes* f. Here, *realizes* is the primitive instance level relation GOC:cjm executes