The "or" ambiguity

• english
• linguistics

#english #linguistics

It happens that there are two types of or in spoken English since or can either be inclusive or exclusive (you see that was an exclusive or).

An exclusive or means that A or B but not both. For example:

I can turn right or turn left.

Usually, one would add either to indicate that the or is exclusive as in:

I can either turn right or turn left.

An inclusive or means that A or B or both are true. This happens when, for example:

I want a lemon or an orange.

which could be the same as:

I want a lemon or an orange or both.

This time there’s no ambiguity, but the or both feels redundant. Alternatively, some may prefer to use and/or to indicate that the or is inclusive:

I want a lemon and/or an orange.

Still, this introduces another redundancy because and/or can be implied by an inclusive or. Off the top of my head I can’t think of any other word in English with a slash in between, so and/or feels like an odd one.

To solve the dilemma when I take notes, I prefer to always use xor for exclusive or and restrict or to only its inclusive meaning. This way everything will be consistent with boolean logic, which was created to be unambiguous.

So the sentences become:

I can turn right xor turn left.

In an inclusive case, the sentence becomes:

I want a lemon or an orange.

Otherwise, if it’s meant to be exclusive (i.e. you don’t want both) it will be:

I want a lemon xor an orange.

Hopefully that addresses some confusion when you come across the word xor in my notes.