A typeset expression:

A special character:

Subscripts and superscripts:

Overscripts and underscripts:

List structures:

A matrix:

Logic operations:

A definite sum:

A special function:

MathMLForm gives MathML for the TraditionalForm expression:

Obtain MathML for the expression in StandardForm:

Convert an expression to MathML:

Use ToExpression to convert MathML back to Wolfram Language syntax:

Use ToExpression to convert from any MathML to the Wolfram Language:

Use Export to generate a MathML document, including semantic markup:

Add formatting via Format:

When an input evaluates to MathMLForm[expr], MathMLForm does not appear in the output:

Out is assigned the value x², not MathMLForm[x^2]:

Even when an output omits MathMLForm from the top level, it is not stripped from subexpressions:

The output does not have MathMLForm in it:

However, the variable e does have MathMLForm in it, which may affect subsequent evaluations:

The product is not evaluated due to the intervening MathMLForm:

Assign variables first and then apply MathMLForm to the result to maintain computability: