How could I draw Venn in mermaid

[cinast]

"Venn"

flowchart TB

subgraph U
    subgraph A
    a1{a1}
    a2{c}
    end

    subgraph B
    b1{b1}
    b2{c}
    end
end

subgraph "A∩b"
c
end

Loading

Mermaid doesn't support venn, at least not in doc.
this "venn" made by flowchart
and... how long will it be updated

[cinast]

flowchart TB

subgraph U
    subgraph A
    a1{a1}
    a2{c}
    end

    subgraph B
    b1{b1}
    b2{c}
    end
end

subgraph "A∩b"
c
end