~のぼる  => To increase N2
Reach level
... おぼえはない => don't remember... N3
Position, perspective
..は, ...が => Compare は and が N5
Compare
が  => but N5
Contrast
が => But... N4
Contrast
が => Well, then N4
How to say the beginning
が => however; but ~ N5
が => Auxiliary words N5
Auxiliary words
だが => But N2
~ようが...まいが => whether or not; regardless N1
うが~うが => Whether A or B N1
Miscellaneous
... だろうが、... だろうが => Whether it's ... or ... N3
Demonstrate by example