What is the mathematical name of np.reshape tensor?

Question

Python

Shalom. I am writing a mat work and then a strange need arose.
How to write in Russian mathematical language what is the change in the shape of the tensor (m, n, t) in (i, j), provided that i + j = m + n + t?
In other words, an analogue of numpy.reshape function where, for example, from numpy.darray with shape = (3, 2, 4) is obtained with shape = (4, 5)
I would call it a convolution, but I'm afraid it's completely different .. In the
convolution, as far as I know, the rank of the tensor (m, n) becomes (m-2, n-2), and here it becomes -1...