pub fn cup_square(
g: &FiniteGroup,
modulus: usize,
n: usize,
f: &[usize],
) -> Vec<usize>Expand description
The cup-square cohomology operation x ↦ x ∪ x : Hⁿ(−; A) → H²ⁿ(−; A). Over Z/2 it is the TOP
Steenrod square Sqⁿ — the first genuine cohomology operation (a natural transformation of the
functor Hⁿ(−;A)), the secondary structure carried by the cohomology the Eilenberg–MacLane spectrum
represents.