Boolean type inference doesn't work with && and || when both variables are new

[onsah]

I noticed that when introducing more than one variable using boolean operators type inference doesn't work as expected.

How to reproduce:

1. Open a Hanfor project
2. Create a new formalization
3. Choose 'Global' scope
4. Choose 'it is always the case that {R} holds' pattern
5. Set R to a && b where a and b are not existing variables.
6. Click 'Save Changes'

Behaviour: Unknown type error for both a and b.
Expected: a and b are inferred as boolean variables.

Note that when one of the variable is already known, the other is inferred as well.

Version: Hanfor v1.0.2-832-ge066698d