data/mathematical/259.mml
<math xmlns='http://www.w3.org/1998/Math/MathML' display='inline'><semantics><mrow><msub><mi>f</mi> <mn>1</mn></msub><mo>+</mo><msub><mi>f</mi> <mn>2</mn></msub><mo>=</mo><mn>2</mn><msub><mi>f</mi> <mn>0</mn></msub></mrow><annotation encoding='application/x-tex'>f_{1}+f_{2}=2f_{0}</annotation></semantics></math>