Learning spells with Zero Arts

I've always thought that having no points in an Art just meant you had a 0 to add to your Lab Total, so someone with Cr 0 and Ig 0 could still learn level 5 CrIg formulaics, just from Int+Magic Theory+Aura, not to mention casting very small sponts. This came as a surprise to my troupe, which mostly assumes you need some xp in an Art to activate it. Can anyone settle this for us, preferably with a citation or other authority?


ArM 5, p. 106 ("training your apprentice") states that you need a season to "open" your Arts. This ends with them at a score of 0 (as opposed to no score). That's kind of like putting experience in an ordinary Ability in order to be able to use it at all.