Tools by Andrew Dupont begins here.

Book 1 - Stuff

Chapter 1 - Generic Objects

Section 1 - Unscrewing

A thing can be unscrewable. A thing is usually not unscrewable.
A thing can be screw-removing. A thing is usually not screw-removing.

Unscrewing is an action applying to one visible thing and one thing.

Understand "unscrew [thing] with [thing]" as unscrewing.
Understand "use [screw-removing thing] on/with [thing]" as unscrewing (with nouns reversed).


[UNSCREWING rules]
Unscrewing rules are an object-based rulebook.

An unscrewing rule for something (called candidate) (this is the can unscrew rule):
	if the candidate is screw-removing:
		rule succeeds;
	otherwise:
		rule fails.

[CAN-BE-UNSCREWED rules]
Can-be-unscrewed rules are an object-based rulebook.

A can-be-unscrewed rule for something (called candidate) (this is the can be unscrewed rule):
	if the candidate is not unscrewable:
		say "I don't think that's possible.";
		rule fails;
	if the candidate is not fixed in place:
		say "It's already unscrewed.";
		rule fails;
	otherwise:
		rule succeeds.


[CHECK/CARRY OUT rules]
Check unscrewing:
	follow the unscrewing rules for the second noun;
	if the rule failed:
		rule fails;
	follow the can-be-unscrewed rules for the noun;
	if the rule failed:
		rule fails;
	otherwise:
		continue the action.

Carry out unscrewing:
	now the noun is not fixed in place.

Tools ends here.