,
Q RXU LQWURGXFWLRQ WR RSHUDWLRQDO
DPSOLILHUV LQ WKH 0D\ LVVXH ZH
H[SODLQHGWKDWRSDPSVDUHVHOGRP
RSHUDWHG³RSHQORRS ́QHDUO\DOZD\V
LQFRUSRUDWLQJVRPHGHJUHHRIQHJDWLYH
IHHGEDFN:LWKRXWQHJDWLYHIHHGEDFN
WKHRSDPSKDVH[WUHPHO\KLJKJDLQ
DQGLVLQKHUHQWO\XQVWDEOH,QLWV³QRU
PDO ́DSSOLFDWLRQWKHRSDPSUHOLHVRQ
QHJDWLYHIHHGEDFNLQRUGHUWRDFWOLNHD
QRUPDODPSOLILHU
+RZHYHUWKHUHLVRQHDSSOLFDWLRQLQ
ZKLFKWKHRSDPSLVRSHUDWHG³ZLGH
RSHQ ́ZLWKQRQHJDWLYHIHHGEDFN7KLV
ZLGHRSHQ RSDPS LV NQRZQ DV WKH
FRPSDUDWRU
:LWKQRQHJDWLYHIHHGEDFNDYHU\
VPDOOVLJQDODSSOLHGWRHLWKHUWKHLQYHUW
LQJRUQRQLQYHUWLQJLQSXWFDXVHVWKH
RXWSXWYROWDJHWRVZLQJWRWKHH[WUHPH
YROWDJHSRVVLEOHLHWKHSRZHUVXSSO\
³UDLO ́YROWDJHV<RXPD\ULJKWO\FRP
SDUHWKLVWRDOLPLWHULQWKLVHOHPHQWDU\
PRGH LWEDVLFDOO\FRQYHUWVDQ\LQSXW
VLJQDOWRDVTXDUHZDYH
%XWUHPHPEHUWKDWRSDPSVKDYHGLI
IHUHQWLDOLQSXWVDYDLODEOH:KHQRSHUDW
LQJZLWKRXWIHHGEDFNWKHRXWSXWYROWDJH
ZLOOVZLQJWRRQHH[WUHPHRUWKHRWKHU
GHSHQGLQJ RQ WKHUHODWLYH YROWDJHV
DSSOLHG WR WKH LQSXWV ,I WKH YROWDJH
DSSOLHGWRWKHLQYHUWLQJLQSXWLVJUHDWHU
WKDQWKDWDSSOLHGWRWKHQRQLQYHUWLQJ
LQSXWWKHRXWSXWYROWDJHZLOOJR³KDUG
QHJDWLYH ́,IWKHYROWDJHDSSOLHGWRWKH
LQYHUWLQJLQSXWLVOHVVWKDQWKDWDSSOLHG
WR WKH QRQLQYHUWLQJ LQSXW WKH RXWSXW
YROWDJHVZLQJV³KDUGSRVLWLYH ́7KLVLVD
YHU\XVHIXOSURSHUW\3HUKDSVWKHPRVW
FRPPRQDSSOLFDWLRQRIWKLVSURSHUW\LV
DVDWKUHVKROGGHWHFWRU
+RZRIWHQGRZHQHHGVRPHGHYLFH
WKDWZLOOWHOOXVZKHQVRPHVSHFLILFYDOXH
RIYROWDJH RURWKHUSDUDPHWHU LVH[
FHHGHG"7KHUHDUHFRXQWOHVVDSSOLFD
WLRQVIRUWKLVIXQGDPHQWDOIXQFWLRQRI
FRXUVHEXWOHW¶VORRNDWDYHU\FRPPRQ
RQHDVLPSOHWLPHU
Tick-Tock
7REHJLQZLWKKRZGRZHDVVRFLDWHWLPH
ZLWK D YROWDJH" 7KH PRVW REYLRXV
DQVZHULVWKH5&WLPHFRQVWDQWDFDSDF
LWRUFKDUJLQJ RUGLVFKDUJLQJ WKURXJKD
UHVLVWRU )LJXUH :KLOH HLWKHU WKH
FKDUJHRUGLVFKDUJHWLPHFRQVWDQWVFDQ
EHXVHGHTXDOO\HIIHFWLYHO\ZHZLOOVWLFN
ZLWKWKHGLVFKDUJHWLPHFRQVWDQWERWK
IRUFRQVLVWHQF\DQGIRUDVOLJKWLQFUHDVH
LQVLPSOLFLW\ZKLFKZLOOEHFRPHHYLGHQW
ODWHURQ:HFDQXVHDPHJRKPUHVLV
WRUDQGDPLFURIDUDGFDSDFLWRUWRJLYH
XVDVHFRQGWLPHFRQVWDQW8QIRUWX
QDWHO\ RUIRUWXQDWHO\GHSHQGLQJRQ\RXU
SRLQWRIYLHZ WKH5&GLVFKDUJHFXUYH
LVQRWDVWUDLJKWOLQH,W¶VDQH[SRQHQWLDO
IXQFWLRQ,QWKLVSDUWLFXODUFDVHZKHQ
RQHVHFRQGHODSVHVWKHYROWDJHDFURVV
WKHFDSDFLWRUZLOOEHRIWKHRULJLQDO
YROWDJH
(DFKVXEVHTXHQWWLPHFRQVWDQWZLOO
UHVXOWLQDYROWDJHYDOXHRIRIWKH
SUHYLRXVWLPHFRQVWDQW$VDUXOHRIOHIW
ELJWRHDFDSDFLWRULVGHHPHGWREH
³IXOO\ ́GLVFKDUJHGDIWHUILYHWLPHFRQ
VWDQWVDWZKLFKSRLQWWKHYROWDJHLVOHVV
WKDQRIWKHLQLWLDOYDOXH)RUWKHVDNH
RIWKLVGLVFXVVLRQKRZHYHUZH¶OORQO\
WDONDERXWWKHILUVWWLPHFRQVWDQW
)URPDSUDFWLFDOVWDQGSRLQWWKHUH¶V
QRWKLQJSDUWLFXODUO\VDFUHGDERXWWKH
FRQYHQWLRQDO WLPH FRQVWDQW :H FDQ
FUHDWHDVHOIGHILQHGWLPHFRQVWDQW )RU
H[DPSOHWKHWLPHLWWDNHVIRUDUHVLVWRU
FDSDFLWRUFRPELQDWLRQWRGLVFKDUJHWR
+$/)WKHLQLWLDOYROWDJHLQVWHDGRI
,QIDFWWKHKDOIOLIHRIUDGLRDFWLYHGHFD\
XVHVWKLVFRQFHSW6RZHFDQWDONDERXW
WKH³KDOIOLIH ́ RI DQ 5& FLUFXLW 7KH
LPSRUWDQWWKLQJWRUHFRJQL]HLVWKDWLWLV
DORJDULWKPLFIXQFWLRQ
6RZKDWVRUWRIFRQWUDSWLRQFDQZH
XVHWKDWZLOOWHOOXVWKDWDFDSDFLWRU¶V
YROWDJHKDVGURSSHGWRKDOIRILWVLQLWLDO
YROWDJH"$FRPSDUDWRULVDJUHDWFKRLFH
IRUWKLVMRE6ROHW¶VSXWWRJHWKHUDKDOI
YROWDJHGHWHFWRUFLUFXLWDVVKRZQLQ
)LJXUH$VDOZD\VZHKLJKO\UHFRP
PHQGWKDW\RXDFWXDOO\DVVHPEOHRXU
H[DPSOHFLUFXLWV
$OWKRXJKVRPHRSDPSVVXFKDV
WKH/0 XVHGLQWKLVFLUFXLWDUHSDU
WLFXODUO\VXLWDEOHDVFRPSDUDWRUVWKH
ZLOODOVRZRUNILQHLQWKLVUROH«
XVXDOO\ $QG DV DOZD\V ZH DUH
DVVXPLQJDELSRODUSRZHUVXSSO\IRU
WKH FRPSDUDWRU LWVHOI W\SLFDOO\
YROWV $ VHSDUDWH YROW VXSSO\ LV
XVHGIRUWKH5&FLUFXLW
,QWKLVFLUFXLW5DQG5IRUPDUHI
HUHQFH YROWDJH GLYLGHU VXSSO\LQJ
YROWVWRWKHQRQLQYHUWLQJLQSXW,IWKH
YROWDJH DW WKH LQYHUWLQJ LQSXW LV DQ\
YDOXHJUHDWHUWKDQYROWVWKHRXWSXW
ZLOOEH/2: LQWKLVFDVHYROWV ,I
WKHYROWDJHDWWKHLQYHUWLQJLQSXWLVDQ\
)LJXUH%DVLFFRPSDUDWRUFLUFXLWDVGHVFULEHGLQWKHWH[W
ANALOG ADVENTURES
BY ERIC P. NICHOLS,* KL7AJ
The Incomparable Comparator
/\OH$YHQXH
1RUWK3ROH$.
HPDLO NODM#FTDPDWHXUUDGLRFRP!
&4$XJXVW 9LVLW2XU:HE6LWH