Phlebotinum
Conditionals
If you teach me the rules, then I will know how to infer the preconditions and results of actions. I will also have a limited understanding of the implications of facts.
Etiology
You can teach me cause and effect, allowing me to set the world in motion.
Simple Reactions
A balloon's state must be empty, full, or broken.
A person's state must be energetic or tired.
A balloon's owner must be a person.
A balloon must have an owner.
Pinkie and Brain are persons.
There is a red balloon and a blue balloon.
Pinkie is energetic.
The red balloon is empty.
Pinkie is the red balloon's owner.
> If a person inflates a balloon, it becomes full.
OK.
> Pinkie inflates the red balloon.
OK.
> What is the red balloon's state?
Full.
I also understand after, when and whenever as conditionals describing cause and effect.
> After a person punctures a balloon, it becomes broken.
OK.
> When a person deflates a balloon, it becomes empty.
OK.
> Whenever a balloon bursts, it becomes broken.
OK.
Multiple Reactions
A cause may have more than one effect:
> When a person inflates a balloon, it becomes full; also the person becomes tired.
OK.
> Pinkie inflates the red balloon.
OK.
> What is the red balloon's state?
Full.
> What is Pinkie's state?
Tired.
Chain Reactions
Effects may themselves be causes, resulting in a cascade of further effects.
> A balloon's neighbor must be a balloon.
OK.
> When a person punctures a balloon, it pops.
OK.
> When a balloon pops, it becomes broken; also its neighbor pops.
OK.
> The blue balloon is the red balloon's neighbor.
OK.
> The red balloon and the blue balloon are full.
OK.
> Pinkie punctures the red balloon.
OK.
> Is the red balloon broken?
Yes.
> Is the blue balloon broken?
Yes.
Causes
I can recognize either actions or changes as causes:
> When a balloon becomes full, its owner becomes tired.
OK.
> When a person inflates a balloon, the person becomes energetic.
OK.
> When a balloon pops, its owner becomes tired.
OK.
But I do not recognize static conditions as causes.
> When a balloon is full, its owner becomes tired.
I am unable to validate the belief that when a balloon is full, then its owner becomes tired.
Instead, you can either restate it as a change in state (“the balloon becomes full”), or you can use the consequently modifier:
> If a balloon is full, consequently its owner is tired.
OK.
When declared as above, the consequence must continue to hold for as long as the antecedent does. (FIXME: this constraint is not actually implemented yet!)
Effects
Likewise, I expect effects to be either actions or state changes:
> When a balloon becomes full, Pinkie pops it.
OK.
> Whenever a balloon becomes full, its owner becomes tired.
OK.
I only understand static conditions as effects when you add the subsequently modifier, or when you use the after conditional:
> When a balloon becomes full, then its owner is tired.
I am unable to validate the belief that when a balloon becomes full, then its owner is tired.
> After a balloon becomes full, its owner is tired.
OK.
> When a balloon becomes full, its owner is subsequently tired.
OK.
Conjunctive Conditions
In order to limit the situations in which a cause results in an effect, you can specify an additional condition:
> If a person inflates a balloon, and the person is tired, then the balloon becomes full.
OK.
> If a person inflates a balloon, and the person is energetic, then the balloon becomes broken.
OK.
> The red balloon is empty.
OK.
> Brain is tired.
OK.
> Pinkie is energetic.
OK.
> Brain inflates the red balloon.
OK.
> What is the red balloon's state?
Full.
> Pinkie inflates the red balloon.
OK.
> What is the red balloon's state?
Broken.
I can only handle one extra condition like this, and it must be combined with the cause via AND (not OR).
Preconditions
You can tell me to enforce a certain condition before an event can take place:
> If a person inflates a balloon, it becomes full.
OK.
> If a person punctures a balloon, it pops.
OK.
> Before a balloon pops, it must be full.
OK.
> Pinkie punctures the red balloon.
But the red balloon is not full.
> Pinkie inflates the red balloon.
OK.
> Pinkie punctures the red balloon.
OK.
Variables
When a rule refers to a variable, its form is important:
> A cloudbuster is a kind of balloon.
OK.
> After a person hugs a cloudbuster, the person becomes energetic.
OK.
> Pinkie hugs the red balloon.
I'm not sure how to interpret that.
Since hugging is only defined specifically for cloudbusters, I’m not sure what it means to hug the generic red balloon.
Disambiguation
You can refer to two different variables having the same form:
> When a balloon refills another balloon, the balloon becomes empty; also the other balloon becomes full.
OK.
> The red balloon refills the blue balloon.
OK.
> What is the red balloon's state?
Empty.
> What is the blue balloon's state?
Full.
Alternatively, you can use ordinal references:
> When a first balloon refills a second balloon, the first balloon becomes empty; also the second balloon becomes full.
OK.
Or be high-falutin:
> When a balloon refills another balloon, the former becomes empty; also the latter becomes full.
OK.
Or use named references:
> When a balloon (the filler) refills another balloon (the fillee), the filler becomes empty; also the fillee becomes full.
OK.
Plurals
You can use plurals when referring to variables:
> When a person inflates any balloons, they become full.
OK.
> Pinkie inflates the red balloon and the blue balloon.
OK.
> Are all balloons full?
Yes.
But the plurality doesn’t have any special meaning; it still applies even when only a single object is involved:
> When a person inflates some balloons, they become full.
OK.
> Pinkie inflates the blue balloon.
OK.
> What is the blue balloon's state?
Full.
Likewise, a non-plural variable still applies when multiple objects are involved:
> When a person inflates a balloon, it becomes full.
OK.
> Pinkie inflates the red balloon and the blue balloon.
OK.
> Are all balloons full?
Yes.
Equivalences
You can teach me how to interchange equivalent conditions.
> If a person holds a balloon, equivalently the person is its owner.
OK.
> Who holds the red balloon?
Pinkie.
> Brain holds the blue balloon.
OK.
> Who is the blue balloon's owner?
Brain.
The equivalent conditions must be either states or relationships, not changes or actions:
> If a person holds a balloon, equivalently the person becomes its owner.
I am unable to validate the belief that if a person holds a balloon, equivalently the person becomes its owner.
(FIXME: I don’t actually know how to discriminate stative from action verbs yet)
Special Events
You can tell me what to do when new objects come into existence:
> After a balloon instantiates, its owner is Pinkie.
OK.
> There is a green balloon.
OK.
> Who is the green balloon's owner?
Pinkie.
And you can prevent instantiation when a given constraint does not hold:
> Before a balloon instantiates, Brain must be energetic.
OK.
> When a person inflates a balloon, the person becomes energetic.
OK.
> There is a green balloon.
But Brain is not energetic.
> Brain inflates the red balloon.
OK.
> There is a green balloon.
OK.