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state_set_simulation_faster (869B)


      1 # State set simulation faster
      2 
      3 idea: decompose [thompson_automaton] into a tree of small [TNFAs]
      4 - two [TNFAs] overlap in at most two states
      5 - do [state_set_simulation] inside each [TNFA] twice: [state_set_simulation_tabulation]
      6   - uses the fact that each simple path has at most one back-edge to say that doing it twice suffices
      7 (myers1992, bille2006)
      8 
      9 ## Word-level parallelism
     10 
     11 other idea: word-level parallelism, reading a block that corresponds to a machine word
     12 - main problem: epsilon transitions
     13 
     14 idea: separator that splits [TNFA] in two halves of roughly equal size such that paths have to go through the separator
     15 
     16 [bille2010regular]
     17 
     18 Limits: cannot do better than Omega(nm/w) for w the word size
     19 
     20 Can go faster: [bille2009faster], divided by log^{1.5}, 4 traversals over the [TNFAs]
     21 
     22 "2D Decomposition algorithm"
     23 
     24 Up: [state_set_simulation], [log_shaving]