|
3 | added 104 characters in body | ||
|
Such homotopies are given by the $\smile_i$-products. Steenrod gives explicit formulas, IIRC, in [Steenrod, N. E. Products of cocycles and extensions of mappings. Ann. of Math. (2) 48, (1947). 290--320. MR0022071], but the easiest is to prove they exists exist using acyclic models. (Maybe Steenrod only deals with $\mathbb Z_2$ coefficients? I don't have access to the paper now :( ) |
||||
|
|
2 | added 216 characters in body; added 63 characters in body | ||
|
Such homotopies are given by the $\smile_i$-products. Steenrod gives explicit formulas, IIRC, in [Steenrod, N. E. Products of cocycles and extensions of mappings. Ann. of Math. (2) 48, (1947). 290--320. MR0022071], but the easiest is to prove they exists using acyclic models. |
||||
|
|
1 |
|
||
|
Such homotopies are given by the $\smile_i$-products. |
||||
