singleknotted
Singleknotted is an informal term used in knot theory to describe a knot that can be transformed into the unknot by a single crossing change. More formally, such knots are said to have unknotting number one. A crossing change is the local operation of switching an overcrossing to an undercrossing (or vice versa) at a single crossing in a knot diagram. If a knot has unknotting number one, a single crossing change suffices to untie it, and no fewer changes can achieve the same result.
Examples and scope: The trefoil knot, the simplest nontrivial knot, is a standard example with unknotting number
Relation to other concepts: Unknotting number is a distinct measure from other knot invariants such as genus
Notation and usage: While singleknotted is used informally in some discussions, the standard terminology in formal