# [isabelle] structured induction

In the following example (taken from
~~/src/HOL/Induct/Common_Patterns.thy) there is apparently unnecessary
duplication.
lemma
fixes n :: nat
shows "P n" and "Q n"
proof (induct n)
case 0 case 1
show "P 0" sorry
next
case 0 case 2
show "Q 0" sorry
next
case (Suc n) case 1
note hyps = `P n` `Q n` (**** this line ... ****)
show "P (Suc n)" sorry
next
case (Suc n) case 2
note hyps = `P n` `Q n` (**** ... duplicated ***)
show "Q (Suc n)" sorry
qed
I want to know how to avoid this duplication. Even more, I have the
common example
lemma
assumes h:"inductiveR x"
and

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