[isabelle] nat properties


i need some properties of the nat.

i couldn't proof the lemma below.
[|(0::int)<a; 0<b; a dvd b|]==> (nat a) dvd (nat b)

is there any theory which include such properties or is there a solution to 
prove this lemma?


This archive was generated by a fusion of Pipermail (Mailman edition) and MHonArc.