[abc] another minor change

The last proposed change was not completely sufficient. The definition of pos must be:

pos(\gamma,\gamma_a,\beta,s,t) := \gamma_a[t\mapsto c / t\mapsto (c \cup \uline{pos(\gamma(s),\beta))}]

instead of just

pos(\gamma,\gamma_a,\beta,s,t) := \gamma_a[t\mapsto c / t\mapsto \uline{pos(\gamma(s),\beta)}]

(equation 15 in the updates PDF)

Eric

--
Eric Bodden
Sable Research Group, McGill University
Montréal, Québec, Canada