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# remove(+Tree0, ++Key, ?Value, -Tree)

Remove a key/value pair from a tree, failing if the key is not present.

Tree0
  A 2-3-4 tree
Key
  The key to remove
Value
  The value corresponding to Key
Tree
  The tree after removal

## Description

If the key Key appears in the tree Tree0, then remove it and attempt to unify its corresponding value with Value. Tree is Tree0 with the key removed.

This predicate should only be called with trees created by other predicates from the tree234 module.

### Fail Conditions

Fails is Key does not appear in Tree0 or if Value does not unify with the corresponding value.

### Resatisfiable

no

## See Also

delete / 3, remove_smallest / 4