(отрывок из статьи на GoTranslators.com)

When I went to high school in Denmark and was one day on my way home in a train, the inspector who checked my travel card said it was not valid in the zone I was in and charged me for a ticket. I contested and said I had checked it when buying the card. The brochure explaining the travel cards said:

"Valid on all trains and buses in 5 chosen zones"

When I had read that, I had interpreted it as the following:

"Valid on (all trains) AND (buses in 5 chosen zones)"

What the writer intended to say was:

"Valid on all (trains and buses) in 5 chosen zones"

using implied parenthesis to make "5 chosen zones" apply to both "trains" and "buses", subordinating "all" to transport means within the 5 zones.

The trouble is that we cannot use logical parenthesis in linguistics even when it would avoid ambiguities like this. This means that if we are not careful how we write every sentence, then we may leave more than one possibility for the reader to place the logical parenthesis, as above, and the reader may understand another meaning that the sentence really has but which was not intended.