data/mathematical/57.mml
<math xmlns='http://www.w3.org/1998/Math/MathML' display='inline'><semantics><mrow><mn>0</mn><mo>→</mo><mi>B</mi><mo>→</mo><mi>A</mi><mo>⊕</mo><mi>B</mi><mo>→</mo><mi>A</mi><mo>→</mo><mn>0</mn></mrow><annotation encoding='application/x-tex'>0\rightarrow B\rightarrow A\oplus B\rightarrow A\rightarrow0</annotation></semantics></math>