x1=fan1=fr1 is a bijective function / isomorphism from x2=fan2 to x3=fan3, with inverse x4, in system / category x5; x1 has an inverse; x1 is a function that is injective and surjective; x2 and x3 are isomorphic; x1 is invertible.
A brapagjvo. See also: atfau'u (shortening of fatfrika'efancu), gauncri (surjection), ficystodraunju (injection), stodraunju. Leave the «ka'e» unstressed and the regular penultimate syllable stressed to distinguish this word from «fatfrika'e fancu», which has 2 stressed syllables, to signal the end of each word.