and i was thinking of (1) something like

dependees

for rules, which is "i want everything that statically exists (in the rule graph) satisfying these filters" (2) something like task/rule progress display which is "i want some selection of products in flight" (3) something like

Select()

for an

@rule

which is "i want this specific product which there should only be a single way to obtain in the subgraph this rule is contained in"