duplicate proof -> duplicate block proof

Author: AshwinSekar

proposals/0204-slashable-event-verification.md

@@ -115,8 +115,8 @@ in Solana's gossip protocol to verify duplicate proofs for use in fork choice.
 
 #### Proof verification
 
-`shred1` and `shred2` constitute a valid duplicate proof if any of the following
-conditions are met:
+`shred1` and `shred2` constitute a valid duplicate block proof if any of the
+following conditions are met:
 
 - Both shreds specify the same index and shred type, however their payloads
   differ