As long as the function name, return statement and parameters are clear, you're fine.

def incr n
    return n + 1

or

let incr(n) = n + 1

or

function incr (n)
    return n + 1

are all quite clear, so you may use them. Try not to be ambiguous with a variable affectation

Remarks

Pseudocode is by definition informal. This topic is meant to describe ways to translate language-specific code into something everyone with a programming background can understand.

Pseudocode is an important way to describe an algorithm and is more neutral than giving a langugage-specific implementation. Wikipedia often uses some form of pseudocode when describing an algorithm

Some things, like if-else type conditions are quite easy to write down informally. But other things, js-style callbacks for instance, may be hard to turn into pseudocode for some people.

This is why these examples may prove useful