⊕ (circled plus)
The direct sum of a sequence of matrices.
Syntax

A ⊕ B[ ⊕ ···]

A, B, ...
are matrices

Description
If A, B, ...
is a sequence of matrices, then A ⊕ B ⊕ ···
returns the block diagonal matrix having A, B, ...
on the diagonal.
Notes
The nary ⊕
operator is implemented by DirectSum
.
Examples
A ≔ ❨❨1, 2❩, ❨3, 4❩❩; B ≔ ❨❨5, 1, 3❩, ❨1, 0, 2❩❩; C ≔ ❨❨5, 1❩, ❨0, 1❩❩;
A ⊕ B ⊕ C
⎛1 2 0 0 0 0 0⎞ ⎜3 4 0 0 0 0 0⎟ ⎜0 0 5 1 3 0 0⎟ ⎜0 0 1 0 2 0 0⎟ ⎜0 0 0 0 0 5 1⎟ ⎝0 0 0 0 0 0 1⎠