Possible ambiguities (I could not get the "suggest edit" to work so now I am opening an issue instead)

[mipals]

Hello,
First of all, as the title suggest, I could not get the "suggest edit" to work, so now I am opening an issue. I hope that is alright.

I believe I have found some ambiguities in the discussing of the mathematical background of BIEs. However, I might just be misunderstanding something.

1. Should the φ and ψ discussed here not be u?

2. It states that $u_\Gamma$ should be in $H^{1/2}$, but it later states that the double-layer potential is going from $H^{-1/2}$?

Cheers,
Mikkel