OAI.ComparatorModel.RecursivePotentials.main

The theorem states (its proof is admitted with sorry) that the defined proposition MainClaim holds. MainClaim asserts that there exist constructions, over index types in universe 0, of the finite rooted tree head structure, the tree-vector spaces, the zero-root tree-vector spaces, the aggregation-vector spaces, and their l^p-coordinate models, such that eleven statements about completions of finite-support vectors on rooted trees hold simultaneously. These comprise: (1) completion statements saying that the root-sum tree space for the sequence tree and for the joined tree, and the zero-root space for the joined tree, are complete, infinite-dimensional, with continuous coordinates extending the vector coordinates, continuous potential fields P and Q extending the finite-tree ones, norm equal to P+Q at the root (or both P and Q at the root in the zero-root case, where the root coordinate vanishes), and with norm-nonincreasing idempotent coordinate projections onto initial subtrees having finite-dimensional range, closed finite-codimensional tails and approximation of tail elements by vectors vanishing on the head, and that XZero and XJoined are reflexive; (2) a main statement giving the lower bound t^3/128 on the averaged modulus of XSigma and XJoined for 0<t<1, a cubic-type uniform convexity inequality (‖x+z‖+‖x-z‖)/2 ≥ ‖x‖+‖z‖^3/(8(2‖x‖+‖z‖)^2) for x supported on a head and z vanishing there, and that no equivalent norm on XSigma, XZero or XJoined has the AUC property (positive modulus at every positive t); (3) positivity of the averaged modulus of XSigma at every positive radius t; (4) a separation statement for XJoined: for each ε>0 there is η in (0,1), equal to min(1/2, logarithmicGamma(2, ε/16)) when ε≤2, such that if ‖x±z_n‖≤1 for all n and the z_n are pairwise at distance at least ε, then ‖x‖≤1-η; (5) properties of the variable-exponent l^2-sum of height-h tree spaces with exponents 1+1/h, namely completeness, reflexivity, separable dual, a root-sum functional ν (nonnegative, definite, subadditive, absolutely homogeneous) bounded above and below by explicit multiples of the l^p norm, dense finitely supported vectors, and finite-rank projections; (6) a recursive characterization of the l^p-model potentials by least pairs, with ν equal to the root P plus Q; (7) for every equivalent norm A on the variable space, the modulus at lower/upper vanishes; (8) the absence of any equivalent AUC norm there; (9) a sixth-power stability inequality and (10) a cubic stability inequality for admissible heads, with explicit constants; and (11) a weak-tail estimate: if x and a weakly null sequence y_j with ‖y_j‖≥ε, 0<ε≤1, satisfy ‖x±y_j‖≤1, then ‖x‖≤θ(ε)<1.