Assertion: grade's level | /r/HasProperty | b2
Facets:
Source sentences:
text: The B system conceived by John Gill in the 1950s was a universal rating scheme for bouldering, having three categories: "B1" was defined as "... the highest level of difficulty in traditional roped climbing", "B2" was harder than B1, or "bouldering level", and the grade "B3" designated a route ascended only once, although tried by others on several occasions.