x_{1} is an injective function (distinctness-preserving function) from x_{2} (domain) to x_{3} (codomain).

This is a brapagjvo (one of its veljvo is the zi'evla "stodraunju"). Let f be the sumti which fills x_{1}; for any y and z in x_{2}, y =/= z iff f(y) =/= f(z).

- stodraunju
- x
_{1}is a function mapping x_{2}(domain) to x_{3}(codomain) such that properties x_{4}(ka) of x_{2}are preserved in its image under x_{1}according to the rules/operations/relations of x_{3}corresponding to those of x_{2}by x_{1}.