only

In logic and related fields such as mathematics and philosophy, "if and only if" (shortened as "iff") is a biconditional logical connective between statements, where either both statements are true or both are false.
The connective is biconditional (a statement of material equivalence), and can be likened to the standard material conditional ("only if", equal to "if ... then") combined with its reverse ("if"); hence the name. The result is that the truth of either one of the connected statements requires the truth of the other (i.e. either both statements are true, or both are false), though it is controversial whether the connective thus defined is properly rendered by the English "if and only if"—with its pre-existing meaning. For example, P if and only if Q means that P is true whenever Q is true, and the only case in which P is true is if Q is also true, whereas in the case of P if Q, there could be other scenarios where P is true and Q is false.
In writing, phrases commonly used as alternatives to P "if and only if" Q include: Q is necessary and sufficient for P, for P it is necessary and sufficient that Q, P is equivalent (or materially equivalent) to Q (compare with material implication), P precisely if Q, P precisely (or exactly) when Q, P exactly in case Q, and P just in case Q. Some authors regard "iff" as unsuitable in formal writing; others consider it a "borderline case" and tolerate its use.In logical formulae, logical symbols, such as






{\displaystyle \leftrightarrow }
and






{\displaystyle \Leftrightarrow }
, are used instead of these phrases; see § Notation below.

You do not have permission to view the full content of this post. Log in or register now.
  1. T

    Help Question: Bot Only

    What is the age consent in the philippines today?
  2. V

    Referral 10 $USDT each! Join here free! Limited time only!

    💵10 $USDT each Hidden content
  3. W

    Help Question: Bot only

    Can i make content in facebook page posting montage in mobile legends?
  4. D

    Tutorial Disney+ 1 month for 8 pesos only, Gcash Promo

    Meron promo sa Gcash Alipay+ rewards ngayon. For only 8 pesos may 1 month Disney+ for First Time Users. So kung di pa registered Gcash cp number mo sa Disney+, pwede mo siya magamit. 1. Punta kayo first sa A+ Rewards ng Gcash 2. Click nyo yun Buy sa Special Packages na may PHP 8.00 3...
  5. D

    VPN PISOFI Selected Vendo Only, No Cap

    PISOFI Wifi häçk Selected Vendo Only Use HTTP CUSTOM VPN Till 9-28-2023 Hidden contentHidden content
  6. S

    For Sale Dito 11 gb DATA (50 pesos only)N/A

    Payment first Thank you.. 😊
  7. D

    VPN PISOFI Selected Only

    PISOFI Wifi häçk Selected Vendo Only Use HTTP CUSTOM VPN Till 10-21-2023 Hidden content
  8. V

    Help Kaja lucky flip event

    sure na ba ito? at ilan pa magagastos kong dias?
  9. M

    Android App ConfigUpdater Via GitHub with token for VPN owner only

    Latest Version 1: Can handle large files 2: enhance User interface 3: support Android 8 to 13 4: no special permission required app link 👇 ConfigUpdater Video tutorial for GitHub Tutorial Token Access
  10. B

    Help Bot only

    Simplify: a²b²-ab-2(2a²b²-5ab+1)
  11. Z

    Closed Question: Bot Only

    mga uri ng hayop na nakatira sa lambak?
  12. F

    Help Bot only

    Omega n is the oscillation of the system without damping which is the frequency
  13. D

    New ml lite 483mb only

    Hidden content ayan guys may new update pina liit pa 🤗 483mb only legend ung default Hero no skin sample normal Layla: ang itsura ay SaberSkin oh diba astigin note: for advance users only(basa po sa tutorial sa mga bago lang 🤗)
  14. G

    Only in GMA

    🖼️Ctto.
  15. M

    For Sale ML with epic and lightborn skin clean bind for 400php only

    Get nyo na rush sale ! Max emblem and lots of heroes May Lightborn Skin and epic skin na !
  16. D

    Closed New ml lite 535mb only

    latest ml data lite make sure po na updated muna yong app sa playstore tyaka nyo i copy paste to thanks for advance user only thanks Hidden content may new ρá†ch na po ang ml kaya need na naman bagong data lite.. close ko na to thanks po sa support ps: try ko ulit maghanap ng update...
  17. K

    Help Bot only

    ..
  18. I

    Help Bot Only

    Create a program in C that you will input days and convert into hours, minute, and seconds.
  19. R

    Men only have 4 moods

  20. I

    For Sale For sale 300 load card globe only for 240 gcash

    For sale 300 load card globe only for 240 gcash
  21. K

    Help Power bank

    recommend powerbank pls yung nasa LAZADA lang yung magaan lang tapos mabilis din mag charge yung 400+ lang sana naghihirap na kase ako T_T
  22. D

    Globe TM Globe Promo Only

    Alam ko marami na sa inyo ang nakakaalam na netong trick sa Globe lang, well sheshare ko na rin sa mga hindi pa. Load lang kayo or kung may Gcash kayo na may laman na ₱133. Mag register kayo sa GlobeOne app yung may "Super Exclusive Globe+99" .(₱99) Tapos "Messages" send nyo sa 8080 etong...
  23. D

    Closed Bot only Biology 1

    Hello bot! I need answer for this and give me their summary of all incorrect and correct answer. 1. Where does a plant obtain the carbon that contributes to its mass? a. The carbon enters the roots in solution. b. The carbon is taken up from soil particles. c. The carbon is fixed by symbiotic...
  24. S

    Nintendo How to get Nba 2k24 for only 56pesos

    Hidden content
  25. T

    Help Question: Bot Only

    Math question. bot testing lang. pa check po picture send ko. pasagot nalang po yung tanong don. maraming salamat.
  26. T

    Help Question: Bot Only

    hi bot, pa help po. topic: "Lack of support from the government" Question: How can you prevent lack of support from the government
  27. G

    Referral GothamHarbor - A fork of Arkham(Max. 10 Only). Airdrop

    Hidden content
  28. G

    Globe TM Hc gtm only no expired no load

    Hidden content Mga brod n sis pa try Po ito config ko kung kakagat dropden
  29. T

    Help Closed

    Closed
  30. E

    BEST GPU (3060) for the Price of 20K only

    Hi guys bka may alam keo GPU worth 20K only as much as posible sana un 3060 Series na. Thank you.
  31. H

    Only in the Philippines, Any thoughts?

    Grabe haha
  32. B

    Closed Closed

    Closed
  33. C

    Help Question: Bot Only

    Bot, What is correct?, MorningLight or Morning Light
  34. B

    Globe TM OPEN CONFIG PRIVATE SDNS TEST ONLY (PUT YOUR OWN WORKING DNS IP)

    Hidden content Please feedback po kung ano yung working dns IP sa location niyo.
  35. D

    Price cap on rice only 'temporary', NEDA says after stakeholders air concern

    Price cap on rice only 'temporary', NEDA says after stakeholders air concern Job Manahan, ABS-CBN News MANILA — The National Economic Development Authority (NEDA) on Sunday sought to allay stakeholders' concerns on the rice price ceiling, which it said was only temporary. President Ferdinand...
  36. D

    VPN PISOFI Selected Non Voucher Only.

    PISOFI Selected Non Voucher Only Untill October 2, 2023 Use HTTP CUSTOM VPN Hidden contentHidden content Speed Depends On Vendo Signal And Internet Upgrade..
  37. S

    Only the elites will understand

  38. M

    For Sale ML account 300php only

    Guyz clean bind with lightborn skin
  39. J

    Help Emergency Calls Only

    Maibalik pa kaya signal tnt Sim ko? Ganito kc yun nag abroad ako year 2021 2years contract ako sa Saudi Kadahilanan yung tnt Sim Hindi ko na roaming may balance pa yun 100,. this August lng din ako nkabalik sa pinas..may pag asa pa kaya Sim ko? Sayang din kc, valid namn sguro hung reason ko...
  40. O

    Help Please answer this (BOT only)

    Please explain this lyrics in english in no less than 5 sentences Mali ba na magkamali ang 'sang tulad ko? Ako ay tao lang din naman na tulad mo Ano ba ang dapat na gawin? Dapat bang kamuhian O dapat ba na tularan ang 'sang tulad ko na tao lang? Pasensiya na (tao lang) Pasensiya na (tao lang)...
  41. I

    BOT ONLY !

    Paano ba maging gwapo ?
  42. L

    Help Bot Only

    your vessel encountered a steering failure while transiting a VTS area with heavy traffic. All actions were already made to normalize the steering of your ship but to no avail. What will be your actions in order for the VTS and vessels in the vicinity to be aware of your situation. What...
  43. K

    Hitachi TV Black screen only after turning on

    Ano po kaya sira nito? Black screen lang pagkabukas. On/off lang din gumaganang button sa remote. Kung sa PC parang OS ang tingin kong sira. Any help po pls
  44. R

    Crypto Free $9 from BINANCE only 5 people get it now

    Mga lods login then Claim nft lang po free lang po yan Link - Binance free 9$
  45. F

    Referral TRX76 TRON STAKING MINING 5 Tron minimum recharge only!

    TRX76 TRON STAKING MINING Minimum Recharge Upgrade 5 Tron / 0.39$ Minimum wí†hdráwal 2 Tron Instant wí†hdráwals!!! Use Binance or OKX wallet or any other wallets for Deposit and Wí†hdráwals Join the Telegram News on the Platform Stake 5 Tron for 1 day = Total Profit 6.23 Tron Stake 26 Tron for...
  46. S

    Help Ano ang murang printer ngayon for school/home use only?

    Any input is appreciated. TIA - yung pwede na din sanang ma order lang online haha
  47. P

    Referral 10M supply only - MINEHEXA - Mining Site

    November 2023 - TOKEN LAUNCH Only 10 million (10M) tokens will be in circulation. Hidden content
  48. F

    Referral TRX76 TRON STAKING MINING minimum recharge 5 Tron only!!!

    TRX76 TRON STAKING MINING Minimum Recharge Upgrade 5 Tron / 0.39$ Minimum wí†hdráwal 2 Tron Instant wí†hdráwals!!! Use Binance or OKX wallet or any other wallets for Deposit and Wí†hdráwals Join the Telegram News on the Platform Stake 5 Tron for 1 day = Total Profit 6.23 Tron Stake 26 Tron for...
  49. D

    VPN PISOFI Selected Non Voucher Only

    Use HTTP CUSTOM VPN Selected PISOFI Non Voucher Vendo Machines Only.. No Capping Full Internet Speed Hidden content
  50. F

    Referral TRX76 TRON STAKING MINING minimum recharge 5 Tron only!!!

    TRX76 TRON STAKING MINING Minimum Recharge Upgrade 5 Tron / 0.39$ Minimum wí†hdráwal 2 Tron Instant wí†hdráwals!!! Use Binance or OKX wallet or any other wallets for Deposit and Wí†hdráwals Join the Telegram News on the Platform Stake 5 Tron for 1 day = Total Profit 6.23 Tron Stake 26 Tron for...
Back
Top