This array is symmetric:

Declare a rank-4 array to be symmetric in three slots:

Then any transposition involving those slots is equivalent to the original tensor:

Symmetry in all slots of a symbolic array:

It can also be specified as follows:

Symmetry in the given slots of a symbolic array:

Symmetric[{}] and Symmetric[{s}] are representations of the absence of symmetry:

Such cases are canonicalized to an empty list of generators:

Specify the symmetry of a symmetrized array:

Specify the symmetry of a symbolic array:

Symmetrize several slots of an array:

Detect symmetric matrices:

A symmetric tensor can also be specified by providing explicit generators with phase :

The Wolfram Language automatically detects the equivalence:

Overlapping sets of symmetric slots give full symmetry over all those slots:

Non-overlapping sets do not give full symmetry. The resulting symmetry is described using generators:

Dimensions must coincide in all symmetry slots: