Primitive Concepts
Arthroid
Order
Junction
Exterior
Bounding
Occupy 1. To each arthroid is assigned a positive integer which is called the order of the arthroid.
2. An arthroid may be said to be the junction of some set of arthroids.
3. An arthroid or set of arthroids may or may not be exterior.
4. If an arthroid or set of arthroids is not exterior it may be fully bounded: if it is exterior it is either partially unbounded or fully unbounded.
Defined Concepts
5. An arthroid of order 1 is called a plere. An arthroid of order two is called a bine. An arthroid of order three is called a trine. An arthroid of order 4 is called a quane.
6. If an arthroid of order A is the junction of a set S of arthroids, then S is said to join to form A. (Symbolically, S >- A or A -<S.) Any subset S' of S is said to participate in joining to form, A, and A is said to be the co-junction of Sf. Symbolically, S' r- A or A-\S'.
7. A set of arthroids is said to fully bound an arthroid A if and only if Ar- every arthroid in S and the arthroids in S are of order one more than the order of A. If A is not exterior and S contains some but not all of the arthroids, of order one more than the order of A, which A participates in joining to form, then A is said to be partially bounded by S. If A is not exterior and if S contains all of the arthroids, of order one more than the order of A, which A/-, then A is said to be fully bounded by S. If A does not s- any arthroid it is said to be unbounded.
Axioms
In the following axioms S and S' will always denote sets of arthroids, while A, A\, A2 etc. will denote single arthroids.
I. If S>- A, then the arthroids in S must all be of the same order, and this must be less than the order of A.
II. Given any two positive integers m and n, with m < n, every arthroid of order n (n-arthroid) is the junction of precisely one collection of m-arthroids. This collection contains (^) arthroids. (See explanation.)
III. If A2r-A\ and S>-A\ where the order of A2 is greater than the order of the arthroids in S, then there is a subset Sf of S such that S'>-A2.
IV. Suppose S >- A where S is a collection of m-arthroids and A is an n- arthroid. Suppose p is an integer such that m < p < n. Then every subset of (£) m-arthroids in S joins to form a p-arthroid which participates in joining to form A.
THEOREM A
If a plere participates in forming a trine, it participates in forming at least two bines.
Proof:
Let Pi be the plere and let T be the trine. By II, T is the junction of precisely 3 pleres. By hypothesis one of these is Pi, and we denote the others,P2, P3. By IV, (Pi,P2)>- a bine which ^-T; call this Bx. By IV, (Pi,P3)>- a bine which r-T\ call this B2. Therefore Pi^-Pi and P\^-B2. (Note: Pi ^ B2 since by II a bine is the junction of precisely one pair of pleres.) The next four theorems are:
B: If two pleres do not form a mutual bine they do not form a mutual trine.
C: A plere that participates in joining to form a bounded bine also participates in joining to form some other bine.
D: If two pleres form more than one mutual bine, then no two of those bines are adjacent.
E: If three bines join to form a trine, each of those bines is the junction of two of the same three pleres that join to form the trine.