A more thorough explanation:

A disputable presumption is a legal inference or assumption that a fact exists, based on the known or proven existence of some other fact or group of facts. It is a presumption that can be challenged or rebutted with other evidence. This shifts the burden of production or persuasion to the opposing party, who can then attempt to overcome the presumption.

For example, in a criminal case, there may be a disputable presumption that a defendant is innocent until proven guilty. However, if the prosecution presents evidence that the defendant committed the crime, the presumption can be challenged and the burden of proof shifts to the defendant to provide evidence of their innocence.

Another example is the disputable presumption that a child under the age of 18 is not capable of making certain legal decisions, such as signing a contract. However, if the child can provide evidence of their competence, the presumption can be challenged and the burden of proof shifts to the opposing party to prove the child's incompetence.