Function table_denominator 

pub fn table_denominator<A, F, P>(
    alloc: &A,
    c: F,
    table_n_vars: usize,
) -> FieldVec<P, A>
where
    A: Allocator,
    F: BinaryField<Underlier: Divisible<u64>>,
    P: PackedField<Scalar = F>,

Build the negated table denominator J - c over the m-variable table cube.

Entry j is iota(j) - c. The logUp denominator for table position j is c - iota(j); the table’s fraction enters the sum of every instance negated, and carrying that negation on the denominator rather than the numerator costs nothing here, where the entries are built anyway.