According to the principles exposed above, in fact, V7/IV, which means the C7 chord, i.e. the dominant seventh chord on the F major scale (C–E–G–B♭), does not represent the tonic because it contains a B♭ which isn't included in the main key, as Beethoven's Symphony No. 1 is written in the key of C major. The chord then resolves on the natural IV (F major) and in the following bar the V7, i.e. G7 (dominant seventh chord on the C major key), is presented.