Research notes on every problem, and a library of the papers behind them. Built from the open erdos repository.
Updated
Source. Chapter 2 and the opening of Chapter 3, printed pp. 1–3, physical pp. 7–9 of the selected thesis, and the completion paragraph on printed p. 18, physical p. 24. Owens imports the finitization method from Morikawa, Gibson, and Nielsen rather than proving it again.
Tuple semantics
The exact node convention is the one on Nielsen's notation page. At an occurrence of a prime , suppose the explicit syntax above it has already fixed a -coordinate , where . An expression
places in the compatible children modulo , ordered by increasing least positive representative in that normalized -coordinate. Every class represented by is intersected with the explicit th child and with the other explicit ancestor conditions on its syntax path. Thus nested occurrences refine the inherited prime-power coordinate: for example, selects a class modulo and is not merely another copy of the first class modulo .
A blank means that this child is still uncovered; means that an earlier package already covers it; and means that both packages are placed in the same child. A numeral records the selected compatible residue condition of modulus . The modulus of an output class is the least common multiple of all explicitly imposed moduli, so an already present absolute prime power is not multiplied in a second time. Context determines the residue, but the modulus signature is independent of that choice.
The arrow
is an infinite mnemonic: at every power of , its first regular children receive the same ordered inputs and its marked last child continues. A scaled arrow such as begins at total -adic exponent .
Only congruence conditions actually displayed in a package contribute to its modulus. A target hole can impose more residue conditions than an output class. Thus a package covering part of a hole is not silently intersected with the full modulus of that hole. This distinction is essential both for coverage and for the no-repeated-modulus check.
Permuting inputs
Let permute the children at every level of a -tree. Replacing each input by merely replaces one compatible -coordinate by another. It preserves the multiset of prime-exponent vectors of all output moduli. It also preserves relative coverage after the same permutation is applied consistently at every occurrence. This proves the uniform prime- input permutation in Owens's imported prime- template and the author's swap of the first two inputs of one prime- entry.
Finite realization
The exact input used here is the finite-arrow theorem reconstructed with Nielsen's source. Its coverage hypothesis is relative: at each occurrence, every displayed input package must cover the corresponding portion of the actual target inside that explicit child. For a finite acyclic expression satisfying this hypothesis and having distinct regular modulus signatures, truncate each marked spine only after reserving a fresh terminal prime. Recursively realize the finitely many regular children, then use the fresh prime to partition and close the final marked class. Choosing distinct terminal primes outside the regular prime alphabet prevents terminal collisions and can force every terminal modulus above .
The finite-arrow theorem does not prove that the regular signatures in a symbolic construction are distinct. That is a separate hypothesis. The certificate page verifies this hypothesis for the explicit prime- through prime- packages and names the imported Nielsen template pages. Later source-compressed allocations remain a separate obligation.