Define x1 to be a named dummy symbol (having a name heretofore unassigned) such that, if it were to exist, it would satisfy condition/have property x2 (condition/ka); let x1 be such that it satisfies/is described by x2.
This is not a standard assertion/claim proposition, instead being an assignment statement/directive (has an implicit "ko"); as such, it does not really have a truth value (or its truth value is TRUE because of itself). A thing such as x1 need not exist, although non-existence is also not implied; this bridi abstains from resolving the question of x1's existence. "ca'e", "ckaji", "da", "poi", "zo'u".