def forward(self, xf):

```
a, b = self.model(torch.ones((self.size, self.size,2)), torch.zeros((self.size, self.size,2)))
c, d = self.model(torch.zeros((self.size, self.size,2)), torch.ones((self.size, self.size,2)))
b_c=b @ c ***Error is shown here***
di_v=torch.div(b_c,d)
fin=a-di_v
yf=fin@xf
yf_abs = torch.sqrt(yf[..., 0] * yf[..., 0] + yf[..., 1] * yf[..., 1])
output = self.softmax(detector_region(yf_abs))
return output
```

for this code, I am getting following error. Any suggestion will be highly appreciatedâ€¦

RuntimeError: Expected batch2_sizes[0] == bs && batch2_sizes[1] == contraction_size to be true, but got false. (Could this error message be improved? If so, please report an enhancement request to PyTorch.)