X-Received: by 2002:a37:b406:0:b0:763:9dbd:8b13 with SMTP id d6-20020a37b406000000b007639dbd8b13mr1074735qkf.14.1687745804597; Sun, 25 Jun 2023 19:16:44 -0700 (PDT) X-Received: by 2002:a25:e70b:0:b0:bc5:4150:8e8d with SMTP id e11-20020a25e70b000000b00bc541508e8dmr12316326ybh.4.1687745804347; Sun, 25 Jun 2023 19:16:44 -0700 (PDT) Path: csiph.com!weretis.net!feeder6.news.weretis.net!news.misty.com!border-2.nntp.ord.giganews.com!nntp.giganews.com!news-out.google.com!nntp.google.com!postnews.google.com!google-groups.googlegroups.com!not-for-mail Newsgroups: sci.logic Date: Sun, 25 Jun 2023 19:16:44 -0700 (PDT) In-Reply-To: Injection-Info: google-groups.googlegroups.com; posting-host=163.182.226.42; posting-account=OWfgwwgAAADQpH2XgMDMe2wuQ7OFPXlE NNTP-Posting-Host: 163.182.226.42 References: <36975c29-e604-41b7-b394-584fe744fec3n@googlegroups.com> <2fa17789-0233-bdce-6515-649372ab98f0@att.net> <7988a26f-8076-4644-9e76-6764c0ec3cdbn@googlegroups.com> <2aee2b7e-2122-4e7c-a2d0-93c9f0b2797en@googlegroups.com> <48dfa2c1-b340-d5df-6c9b-20e0e8af32fc@att.net> <3f7a0c10-3adb-1084-4ead-003a17206c06@att.net> <839e90d7-d188-4176-ae9f-50ac5fe00aa2n@googlegroups.com> <02d3311b-10c4-4efc-9b12-0918c4c41dfcn@googlegroups.com> <5bcaf0c7-1ac5-4d9c-9973-dfd3e7e644f8n@googlegroups.com> <3158b89a-0948-4b2a-a31e-cda125c3d544n@googlegroups.com> <6c880f28-f476-494d-9e59-ec910289581dn@googlegroups.com> <4f036404-4ba6-4b26-941b-840fffc8cafcn@googlegroups.com> <252e87f5-dc27-4e27-8f3a-694a1ca73867n@googlegroups.com> <9ff00bf1-63a3-4f3f-9692-6035b896d699n@googlegroups.com> <8b197d2a-cf8d-47b0-9f40-342faa834185n@googlegroups.com> <2f966fea-7ef8-4e2f-8c23-843829cfc66en@googlegroups.com> <0b995708-d3bc-489e-af93-5e67f5a473fcn@googlegroups.com> <6957ff30-34e1-4249-86bb-45b87b9fc44en@googlegroups.com> <6250b6a6-9f40-434a-a3ff-bc279e5e3c61n@googlegroups.com> <3f406621-7ba6-4325-8acf-fbcc91d1af22n@googlegroups.com> <542cc78f-0fb0-4af8-add5-d07b2556c7dcn@googlegroups.com> <812b4cb9-4010-4947-a857-15a087bee814n@googlegroups.com> <9e5f72ce-9f45-4f78-9e26-d011b7fcde87n@googlegroups.com> <402183bc-2dc1-4aad-8023-0bf272edd48fn@googlegroups.com> <7b216411-562c-4dda-a70f-db31effdc777n@googlegroups.com> <3bd45ef9-4e2e-4101-b1db-7efc02d2dbf8n@googlegroups.com> <73406ded-a493-4b6c-9033-2827fc6f4d60n@googlegroups.com> <71ac74bc-2122-41da-90ed-6d6b9dac6a0an@googlegroups.com> <144db62b-bef3-4697-ab85-437b8963fbdbn@googlegroups.com> <998303d5-ebb7-4bb4-aebc-fe6371fb8420n@googlegroups.com> <392bfe5c-7f4e-422b-8fcd-af9d1f4b2179n@googlegroups.com> <84255547-eda7-488e-b966-9bccd42d9b0fn@googlegroups.com> <7841bc16-06ca-4936-8cee-dc84e8341d9an@googlegroups.com> <37f78d5b-45fc-4ed3-94b9-0acf27b615c8n@googlegroups.com> <239b2b8c-4944-4668-af38-d32bc55c6306n@googlegroups.com> <0a30b71f-2fad-40b4-9321-a1d0bcba3e8dn@googlegroups.com> User-Agent: G2/1.0 MIME-Version: 1.0 Message-ID: <92abc2fa-8270-4e94-a87e-6a5048fca8can@googlegroups.com> Subject: Re: Why predictions about the future have no truth value From: Dan Christensen Injection-Date: Mon, 26 Jun 2023 02:16:44 +0000 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Lines: 53 Xref: csiph.com sci.logic:254972 On Sunday, June 25, 2023 at 7:29:39=E2=80=AFPM UTC-4, Mild Shock (aka Mr. C= ollapse) wrote: [snip] >=20 > If it is light, it is day.=20 > But it is not the case that it is day.=20 > =E2=80=94=E2=80=94=E2=80=94=E2=80=94=E2=80=94=E2=80=94=E2=80=94=E2=80=94= =E2=80=94=E2=80=94=E2=80=94=E2=80=94=E2=80=94=E2=80=94=E2=80=94=E2=80=94=E2= =80=94=E2=80=94=E2=80=94=E2=80=94=E2=80=94=20 > Therefore it is not the case that it is light.=20 >=20 This is an application of the contrapositive rule (line 4) in propositional= logic. For any logical propositions A and B, we have [A =3D> B] & ~B =3D> = ~A. 1 [A =3D> B] & ~B Premise 2 A =3D> B Split, 1 3 ~B Split, 1 4 ~B =3D> ~A Contra, 2 5 ~A Detach, 4, 3 6 [A =3D> B] & ~B =3D> ~A Conclusion, 1 > Lets assume that light is temporally a little bit before day,=20 > it takes light speed to travel from sun to earth and make=20 > day, then the inference goes backward in time. > So propositional logic can move forward and backward.=20 What are your variables for distance and time? > Because conclusions are like fill in the blanks. They=20 > can answer the past or the future. Your little buddy AP really seems to be getting to you, Mr. Collapse. (Hee= , hee!) Dan Download my DC Proof 2.0 freeware at http://www.dcproof.com Visit my Math Blog at http://www.dcproof.wordpress.com