Editing Heaviside step function (section)

==Relationship with Dirac delta==
The [[Dirac delta function]] is the [[weak derivative]] of the Heaviside function:
<math display="block">\delta(x)= \frac{d}{dx} H(x).</math>
Hence the Heaviside function can be considered to be the [[integral]] of the Dirac delta function. This is sometimes written as
<math display="block">H(x) := \int_{-\infty}^x \delta(s)\,ds</math>
although this expansion may not hold (or even make sense) for {{math|''x'' {{=}} 0}}, depending on which formalism one uses to give meaning to integrals involving {{mvar|δ}}. In this context, the Heaviside function is the [[cumulative distribution function]] of a [[random variable]] which is [[almost surely]] 0. (See [[Constant random variable]].)