rename
set-union
by morphism
:set → dataset;
:elem → data;
∅ → ∅;
++ → ++;
# → #;
{ } → { };
∪ → ∪;
∩ → ∩;
\ → \;
-- → --;
∈ → ∈;
⊆ → ⊆;
s → ds;
s0 → ds0;
s1 → ds1;
s2 → ds2;
a → d;
b → d0;
c → d1
end rename