Reference: directSum

directSum(S1, S2) = S1 ⊕ S2 returns the direct sum of the sets S1 and S2, both containing real vectors of the same dimension.

Example:

s1 ≔ {❨1, 2❩, ❨3, 5❩}

{ ❨1, 2❩, ❨3, 5❩ }

s2 ≔ {❨5, 7❩, ❨2, 4❩}

{ ❨5, 7❩, ❨2, 4❩ }

s1 ⊕ s2

{ ❨6, 9❩, ❨3, 6❩, ❨8, 12❩, ❨5, 9❩ }