(When I say 'by addition' I mean the expressions in which it turns out that we are saying the same thing twice, as in these instances.) And if this is true, coupled terms also, like 'odd number', will not be definable (but this escapes our notice because our formulae are not accurate.).
Eta hau egia baldin bada, bi osagaiz osaturikoek ere ez dute definiziorik izango, esate baterako zenbaki bakoitiak.