- Should there be a comma in "for all"-sentences? For example, is the comma in the following sentence correct?
For all b ∈ B, there is an a ∈ A such that f(a) = b.
- Suppose that one wants to start a sentence with "In most cases". Should there be a comma after that? For example, is the comma in the following sentence correct?
In most cases, (a + b)² = a² + b² is false.