Hello !

I’m currently having some trouble with a quite simple task, so here I am.

I have a tensor A of size [N, T, K], and a tensor B of size [K, C].

I want to compute a tensor Y of size [N, T, C] according to the following algorithm:

```
for i in range(N):
for j in range(T):
for l in range(C):
Y[i, j, l] = 0
for k in range(K):
Y[i, j, l] += A[i, j, k] * B[k, l]
```

I’ve tried many strange thing (always ending with a “RuntimeError: the size of … must match the size of …”), but cannot find an efficient way to vectorize this.

I feel like it’s a perfect job for einsum, but didn’t find the correct notation.

Thanks for reading !