MathML

MathML is a markup language for mathematical notation, structure and content on the web. Its elements describe expressions within a document rather than reducing a formula to a flat character string. MathML Core specifies a subset suited to web browser implementation; the cited 24June2025 document is a Candidate Recommendation Snapshot.^[ref]

Consider the typeset fraction $\frac{x+1}{2}$. A presentation encoding is <math xmlns="http://www.w3.org/1998/Math/MathML"><mfrac><mrow><mi>x</mi><mo>+</mo><mn>1</mn></mrow><mn>2</mn></mfrac></math>. The mi, mo and mn elements identify a symbolic name, an operator and numbers. The mrow groups the numerator; the two children of mfrac provide the numerator and denominator.^[ref]

Grouping changes the represented expression. At $x=3$, the intended fraction gives $(3+1)/2=2$, whereas $x+1/2=7/2$. This arithmetic illustrates the meaning assigned to the structure; MathML presentation markup does not itself execute the calculation. Maintaining a structured representation helps document tools manipulate a formula and lets layout follow its mathematical grouping.