claimroutineinferred_dep

Symbol prescription gives K·1_B = 0

Prescribed Legendre symbols give K1B=0K\mathbf1_B=0
kernel vector property for the block argument
Claim·§3.4 One parameter for both twists·inside lemOne squarefree n serving both twists

Statement (paper)

With the above prescription of the symbols [qi/qb]=[qb/qi]=Cbi[q_i/q_b]=[q_b/q_i]=C_{bi} for b∈Bb\in B, i∈Ii\in I, [q0/qb]=∑i∈ICbi[q_0/q_b]=\sum_{i\in I}C_{bi} for b∈Bb\in B (with reverse symbols given by reciprocity), all other off-diagonal symbols incident with II equal to zero, and the q0q_0--JJ symbols free, the matrix KK satisfies K1B=0K\mathbf1_B=0 on both supports Q=PQ=P and Q=P∪JQ=P\cup J.

In plain English

With the prescribed Legendre-symbol values between the auxiliary primes indexed by II, the primes of BB, and the prime q0q_0 (symbols between q0q_0 and JJ left free), the matrix KK kills the all-ones vector on BB, i.e. K1B=0K\mathbf1_B=0, on both supports Q=PQ=P and Q=P∪JQ=P\cup J.

Why it's here

This checks that the chosen symbols make the row sums over BB of KK vanish. The cancellation uses the fixed sums over BB and JJ from the previous claim, and the choice [q0/qb]=∑iCbi[q_0/q_b]=\sum_i C_{bi} compensates the contribution of the II-primes. It gives the kernel-vector property used in the block-matrix argument for M0M_0 in the next claim and thus toward the matrix target of the lemma.
Classified routine:
A direct verification: substituting the prescribed Legendre symbols and using the fixed B- and J-sums from the earlier claim (with quadratic reciprocity) shows that the row sums over B cancel. It is linear-algebra bookkeeping inside the lemma's construction, not a new idea.

Sources

PaperOpen
Section
§3.4 One parameter for both twists
Page
—
Label
—
Line
sections/03-parity.tex:627
Leannot aligned

Phase 2 aligns this node to a Lean declaration.

Friction

  • info
    inferred_dep
    outline: "Symbol prescription ensures K 1_B = 0" rests on claim-par-simultaneous-matrices-1