123 ÷ 4/5 + 6 | 7 x 8

    = 123 ÷ 0.8 + 6 | 56

    =    153.75 + 6 | 56

    =        159.75 | 56

    = 2.85267 857142 857142 857142 857142 857142 857142 857142 857142 857142...

i.e. here | acts as a low precedence division operator, ÷ as an ordinary precedence division operator like infix / and the 'closefix' rational notation 3/4 has the highest precedence in my programming language

n.b. in case you were wondering P v Q is used for Boolean Or.