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[jean-francois.monin AT imag.fr]

Roland Zumkeller a ecrit :
 > (looks like we forgot to cc the list - citations are below)
 > 
 > As Jean-Christophe Filliâtre suggested in a recent post, proof terms 
 > constructed by a script are  rechecked by the "Save" command. Still it 
 > seems that "Save" cleverly reuses some of the judgements that have 
 > already been obtained from the kernel by the script (thus obscuring the 
 > total checking time), as shown by this example:
 >    Variable P : nat -> Prop.
 >    Hypothesis H : P (500*100 - 500*100).
 > 
 >    Lemma P_0 : P 0.
 >    exact H. (* takes a long time *)
 >    Save. (* takes little time *)

The difference is not that big : Time Save takes yields about 1/2 of
Time Exact (measured with larger values than 500*100).

In the case of this lemma, the difference comes probably from
the reduction algorithm in use.

  Jean-Francois

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