May the provisions in a divorce be changed afterwards?
Unless there is a provision in the separation agreement to do so, they cannot. However, there is a provision in the law to amend spousal or child support based upon a change of circumstances.
The only other provision reasonably available is fraud. If a party commits fraud in the negotiation of an agreement, it may allow for a change in the agreement to correct it.
There is also a provision in the law to correct mistakes in drafting. However, usually the mistake must not be unilateral, that is, only one party believes that the language is in error.