Sentence:  <font face="Courier">5.7.T ( <WSD>Unification theorem</WSD> ) For any two terms or formulas/  without quantifiers X and Y, the following holds./ (i) The <WSD>unification</WSD> algorithm UNIF<sub>1</sub>, applied to X, Y,/  terminates after a finite number of steps./ (ii) {X, Y} is unifiable iff UNIF<sub>1</sub> so indicates upon ter-/  mination. Moreover, the substitution &sigma; then available as out-/  put is a most general unifier of {X, Y}.</font> 
Meaning of the word marked with <WSD> tags:  Given two terms, their join with respect to a specialisation order.