21 lines
504 B
Text
21 lines
504 B
Text
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z0=(0,0);
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z1=(1.5gu,0);
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z2=(0,-gu);
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z3=(1.5gu,-gu);
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path ac,ab;
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label(btex $\mathtt{[a]}$ etex,z0);
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label(btex $\mathtt{[b]}$ etex,z1);
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label(btex $\mathtt{Maybe\ a}$ etex,z2 shifted (-u,0));
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label(btex $\mathtt{Maybe\ b}$ etex,z3 shifted (u,0));
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drawEdge(z0,z1,"\mathtt{fmap_{[]}\ f}");
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drawEdge(z2,z3,"\mathtt{fmap_{Maybe}\ f}");
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ab:=edge(z0,z2);
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drawarrow ab;
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label.lft(btex $\mathtt{toMaybe}$ etex,midpoint(ab));
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ac:=edge(z1,z3);
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drawarrow ac;
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label.rt(btex $\mathtt{toMaybe}$ etex,midpoint(ac));
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