Readonlydefinitewhether every closure the variable may hold surely has such a write
Readonlyentrieseach definition with the call writing it and whether it surely does
Readonlyidsthe definitions written into the frames
Readonlywritersthe calls writing them, which a read reaches as well to keep them in a slice
What the frames of the closures one variable holds bind to a name, see InGraphIdentifierDefinition#closureFrame.