# hanoi-3 — a taught game definition. Lines starting with # are skipped by import.
# After `tmct import --file hanoi-3.txt`, try this in `tmct chat` (or via --prompt):
#
#   disk-1 rests on disk-2. disk-2 rests on disk-3. disk-3 rests on peg-a.
#   the goal is that every disk rests on peg-c. solve it.
#
# Variations, each stretching a different direction:
#   scale      — first teach: "disk-4 is a disk."
#                then: "disk-1 is smaller than disk-4. disk-2 is smaller than disk-4.
#                disk-3 is smaller than disk-4."
#                then: "disk-1 rests on disk-2. disk-2 rests on disk-3. disk-3 rests on
#                disk-4. disk-4 rests on peg-a." — same goal. 15 moves (2^4 - 1).
#                Every smaller-than pair is taught: the relation is stored as given and
#                is not chased transitively, so disk-3 < disk-4 alone leaves disk-1 and
#                disk-2 with no legal move onto disk-4 and no plan exists.
#   any start  — disk-1 rests on peg-b. disk-2 rests on peg-c. disk-3 rests on peg-a.
#                the goal is that every disk rests on peg-c. solve it.
#   other goal — same start, "the goal is that every disk rests on peg-b. solve it."
#   partial    — "the goal is that disk-3 rests on peg-c. solve it."
#                (a one-fact goal; exercises the non-universal goal frame)
#   legality   — "what moves are legal now?"  (findReachableSet, one ply, no plan)
#   read-back  — "what rests on disk-2?" / "is disk-1 clear?"  (plain fact questions,
#                no planning involved)
a disk is a kind of game piece.
a peg is a kind of place.
disk-1 is a disk. disk-2 is a disk. disk-3 is a disk.
peg-a is a peg. peg-b is a peg. peg-c is a peg.
disk-1 is smaller than disk-2. disk-1 is smaller than disk-3.
disk-2 is smaller than disk-3.
you can move a disk onto a peg.
you can move a disk onto a disk.
to move a disk onto a target, nothing may rest on the disk.
to move a disk onto a target, nothing may rest on the target.
to move a disk onto a disk, the disk must be smaller than the target.
moving a disk onto a target makes the disk rest on the target.
a disk renders as a block. a peg renders as a slot.