50_a_history_of_qed
The current implementation of regular expressions in Bell Labs research software uses algorithms close to those in Ken's CTSS and Multics versions, particularly the latter, because they don't try to compile to machine code.

0050_0001__The_0050_0003__implementation the_implementation 0050_0002__current current 0050_0001__The_0050_0003__implementation->0050_0002__current [attrib] 0050_0006__expressions expressions 0050_0001__The_0050_0003__implementation->0050_0006__expressions of 0050_0010__research_0050_0011__software research_software 0050_0001__The_0050_0003__implementation->0050_0010__research_0050_0011__software in 0050_0005__regular regular 0050_0006__expressions->0050_0005__regular [attrib] 0050_0008__Bell_0050_0009__Labs bell_labs 0050_0010__research_0050_0011__software->0050_0008__Bell_0050_0009__Labs [modifier] 0050_0012__uses uses 0050_0012__uses->0050_0001__The_0050_0003__implementation [arg0] 0050_0013__algorithms algorithms 0050_0012__uses->0050_0013__algorithms [arg1] 0050_0014__close close 0050_0013__algorithms->0050_0014__close [attrib] 0050_0016__those those 0050_0014__close->0050_0016__those to 0050_0023__versions versions 0050_0016__those->0050_0023__versions in 0050_0021__and and 0050_0023__versions->0050_0021__and [modifier] 0050_0018__Ken ken 0050_0023__versions->0050_0018__Ken [gen] 0050_0020__CTSS ctss 0050_0021__and->0050_0020__CTSS [conj1] 0050_0022__Multics multics 0050_0021__and->0050_0022__Multics [conj2] 0050_0026__the the 0050_0025__particularly particularly 0050_0026__the->0050_0025__particularly [qual] 0050_0027__latter latter 0050_0026__the->0050_0027__latter [attrib] 0050_0029__because because 0050_0029__because->0050_0012__uses [scope] 0050_0032__n't n't 0050_0029__because->0050_0032__n't [restriction] 0050_0031__do_0050_0033__try do_try 0050_0032__n't->0050_0031__do_0050_0033__try [scope] 0050_0035__compile compile 0050_0031__do_0050_0033__try->0050_0035__compile [arg1] z_0050_5017 _ 0050_0031__do_0050_0033__try->z_0050_5017 [arg0] 0050_0035__compile->z_0050_5017 [arg0] 0050_0037__machine_0050_0038__code machine_code 0050_0035__compile->0050_0037__machine_0050_0038__code to[nim] z_0050_5013 _ z_0050_5013->0050_0023__versions [arg0] z_0050_5013->0050_0026__the [prd]
arc(r_0050_0001__The_r_0050_0003__implementation,r_0050_0002__current,attrib).
arc(r_0050_0001__The_r_0050_0003__implementation,r_0050_0006__expressions,r_0050_0004__of).
arc(r_0050_0001__The_r_0050_0003__implementation,r_0050_0010__research_r_0050_0011__software,r_0050_0007__in).
arc(r_0050_0006__expressions,r_0050_0005__regular,attrib).
arc(r_0050_0010__research_r_0050_0011__software,r_0050_0008__Bell_r_0050_0009__Labs,modifier).
arc(r_0050_0012__uses,r_0050_0001__The_r_0050_0003__implementation,arg0).
arc(r_0050_0012__uses,r_0050_0013__algorithms,arg1).
arc(r_0050_0013__algorithms,r_0050_0014__close,attrib).
arc(r_0050_0014__close,r_0050_0016__those,r_0050_0015__to).
arc(r_0050_0016__those,r_0050_0023__versions,r_0050_0017__in).
arc(r_0050_0021__and,r_0050_0020__CTSS,conj1).
arc(r_0050_0021__and,r_0050_0022__Multics,conj2).
arc(r_0050_0023__versions,r_0050_0018__Ken,gen).
arc(r_0050_0023__versions,r_0050_0021__and,modifier).
arc(r_0050_0026__the,r_0050_0025__particularly,qual).
arc(r_0050_0026__the,r_0050_0027__latter,attrib).
arc(r_0050_0029__because,r_0050_0012__uses,scope_).
arc(r_0050_0029__because,r_0050_0032__n_apos_t,restriction_).
arc(r_0050_0031__do_r_0050_0033__try,r_0050_0035__compile,arg1).
arc(r_0050_0031__do_r_0050_0033__try,z_0050_5017,arg0).
arc(r_0050_0032__n_apos_t,r_0050_0031__do_r_0050_0033__try,keep_scope).
arc(r_0050_0035__compile,r_0050_0037__machine_r_0050_0038__code,r_0050_0036__to__nim).
arc(r_0050_0035__compile,z_0050_5017,arg0).
arc(z_0050_5013,r_0050_0023__versions,arg0).
arc(z_0050_5013,r_0050_0026__the,prd).


IP-MAT NP-SBJ D The ADJP ADJ current N implementation PP P-ROLE of NP ADJP ADJ regular NS expressions PP P-ROLE in NP NLYR NPR Bell NPR Labs N research N software VBP uses NP-OB1 NS algorithms ADJP ADJ close PP P-ROLE to NP D;_nphd_ those PP P-ROLE in NP NP-GEN NPR Ken GENM 's NLYR NLYR NLYR NPR CTSS CONJP CONJ and NLYR NPR Multics NS versions PUNC , PRN NP ADVP ADV particularly D the ADJP ADJ latter PUNC , PP-SCON P-CONN because IP-ADV NP PRO they DOP do NEG;_clitic_ n't VB try IP-INF-OB1 TO to VB compile PP-NIM P-ROLE to NP N machine N code PUNC .
( (IP-MAT (NP-SBJ (D The;{the})
                  (ADJP (ADJ current;{current}))
                  (N implementation;{implementation})
                  (PP (P-ROLE of;{of})
                      (NP;{CURRENT_REGEX} (ADJP (ADJ regular;{regular}))
                                          (NS expressions;{expression})))
                  (PP (P-ROLE in;{in})
                      (NP (NLYR (NPR Bell;{Bell})
                                (NPR Labs;{Labs}))
                          (N research;{research})
                          (N software;{software}))))
          (VBP uses;{use})
          (NP-OB1 (NS algorithms;{algorithm})
                  (ADJP (ADJ close;{close})
                        (PP (P-ROLE to;{to})
                            (NP (D;_nphd_ those;{those})
                                (PP (P-ROLE in;{in})
                                    (NP (NP-GEN;{KEN} (NPR Ken;{Ken})
                                                      (GENM <apos>s))
                                        (NLYR (NLYR (NLYR (NPR CTSS;{CTSS}))
                                                    (CONJP (CONJ and;{and})
                                                           (NLYR (NPR Multics;{Multics})))))
                                        (NS versions;{version})
                                        (PUNC ,)
                                        (PRN (NP (ADVP (ADV particularly;{particularly}))
                                                 (D the;{the})
                                                 (ADJP (ADJ latter;{latter}))))))))))
          (PUNC ,)
          (PP-SCON (P-CONN because;{because})
                   (IP-ADV (NP;{CURRENT_REGEX} (PRO they;{they}))
                           (DOP do;{do})
                           (NEG;_clitic_ n<apos>t;{not})
                           (VB try;{try})
                           (IP-INF-OB1 (TO to;{to})
                                       (VB compile;{compile})
                                       (PP-NIM (P-ROLE to;{to})
                                               (NP (N machine;{machine})
                                                   (N code;{code}))))))
          (PUNC .))
  (ID 50_a_history_of_qed))