Reading and writing is modelled in CSP using actions containing the sym-
bols ? and !. These reading and writing actions are synchronous and there is a one-
to-one relationship between occurrences of pairs of these actions. It is cumbersome to
ease the restriction of synchronous execution of the read and write actions. For this
reason we introduce the half-asynchronous parallel operator that acts on actions con-
taining the symbols ¿ and ¡ and study the impact on a Vertex Removing Synchronised
Product.
