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| Type | Label | Description | ||||||||||||||||||||||||||||||
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| Statement | ||||||||||||||||||||||||||||||||
| Theorem | pm14.122b 45501* | Theorem *14.122 in [WhiteheadRussell] p. 185. (Contributed by Andrew Salmon, 9-Jun-2011.) | ||||||||||||||||||||||||||||||
| ⊢ (𝐴 ∈ 𝑉 → ((∀𝑥(𝜑 → 𝑥 = 𝐴) ∧ [𝐴 / 𝑥]𝜑) ↔ (∀𝑥(𝜑 → 𝑥 = 𝐴) ∧ ∃𝑥𝜑))) | ||||||||||||||||||||||||||||||||
| Theorem | pm14.122c 45502* | Theorem *14.122 in [WhiteheadRussell] p. 185. (Contributed by Andrew Salmon, 9-Jun-2011.) | ||||||||||||||||||||||||||||||
| ⊢ (𝐴 ∈ 𝑉 → (∀𝑥(𝜑 ↔ 𝑥 = 𝐴) ↔ (∀𝑥(𝜑 → 𝑥 = 𝐴) ∧ ∃𝑥𝜑))) | ||||||||||||||||||||||||||||||||
| Theorem | pm14.123a 45503* | Theorem *14.123 in [WhiteheadRussell] p. 185. (Contributed by Andrew Salmon, 9-Jun-2011.) | ||||||||||||||||||||||||||||||
| ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (∀𝑧∀𝑤(𝜑 ↔ (𝑧 = 𝐴 ∧ 𝑤 = 𝐵)) ↔ (∀𝑧∀𝑤(𝜑 → (𝑧 = 𝐴 ∧ 𝑤 = 𝐵)) ∧ [𝐴 / 𝑧][𝐵 / 𝑤]𝜑))) | ||||||||||||||||||||||||||||||||
| Theorem | pm14.123b 45504* | Theorem *14.123 in [WhiteheadRussell] p. 185. (Contributed by Andrew Salmon, 9-Jun-2011.) | ||||||||||||||||||||||||||||||
| ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → ((∀𝑧∀𝑤(𝜑 → (𝑧 = 𝐴 ∧ 𝑤 = 𝐵)) ∧ [𝐴 / 𝑧][𝐵 / 𝑤]𝜑) ↔ (∀𝑧∀𝑤(𝜑 → (𝑧 = 𝐴 ∧ 𝑤 = 𝐵)) ∧ ∃𝑧∃𝑤𝜑))) | ||||||||||||||||||||||||||||||||
| Theorem | pm14.123c 45505* | Theorem *14.123 in [WhiteheadRussell] p. 185. (Contributed by Andrew Salmon, 9-Jun-2011.) | ||||||||||||||||||||||||||||||
| ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (∀𝑧∀𝑤(𝜑 ↔ (𝑧 = 𝐴 ∧ 𝑤 = 𝐵)) ↔ (∀𝑧∀𝑤(𝜑 → (𝑧 = 𝐴 ∧ 𝑤 = 𝐵)) ∧ ∃𝑧∃𝑤𝜑))) | ||||||||||||||||||||||||||||||||
| Theorem | pm14.18 45506 | Theorem *14.18 in [WhiteheadRussell] p. 189. (Contributed by Andrew Salmon, 11-Jul-2011.) | ||||||||||||||||||||||||||||||
| ⊢ (∃!𝑥𝜑 → (∀𝑥𝜓 → [(℩𝑥𝜑) / 𝑥]𝜓)) | ||||||||||||||||||||||||||||||||
| Theorem | iotaequ 45507* | Theorem *14.2 in [WhiteheadRussell] p. 189. (Contributed by Andrew Salmon, 11-Jul-2011.) | ||||||||||||||||||||||||||||||
| ⊢ (℩𝑥𝑥 = 𝑦) = 𝑦 | ||||||||||||||||||||||||||||||||
| Theorem | iotavalb 45508* | Theorem *14.202 in [WhiteheadRussell] p. 189. A biconditional version of iotaval 6512. (Contributed by Andrew Salmon, 11-Jul-2011.) | ||||||||||||||||||||||||||||||
| ⊢ (∃!𝑥𝜑 → (∀𝑥(𝜑 ↔ 𝑥 = 𝑦) ↔ (℩𝑥𝜑) = 𝑦)) | ||||||||||||||||||||||||||||||||
| Theorem | iotasbc5 45509* | Theorem *14.205 in [WhiteheadRussell] p. 190. (Contributed by Andrew Salmon, 11-Jul-2011.) | ||||||||||||||||||||||||||||||
| ⊢ (∃!𝑥𝜑 → ([(℩𝑥𝜑) / 𝑦]𝜓 ↔ ∃𝑦(𝑦 = (℩𝑥𝜑) ∧ 𝜓))) | ||||||||||||||||||||||||||||||||
| Theorem | pm14.24 45510* | Theorem *14.24 in [WhiteheadRussell] p. 191. (Contributed by Andrew Salmon, 12-Jul-2011.) | ||||||||||||||||||||||||||||||
| ⊢ (∃!𝑥𝜑 → ∀𝑦([𝑦 / 𝑥]𝜑 ↔ 𝑦 = (℩𝑥𝜑))) | ||||||||||||||||||||||||||||||||
| Theorem | iotavalsb 45511* | Theorem *14.242 in [WhiteheadRussell] p. 192. (Contributed by Andrew Salmon, 11-Jul-2011.) | ||||||||||||||||||||||||||||||
| ⊢ (∀𝑥(𝜑 ↔ 𝑥 = 𝑦) → ([𝑦 / 𝑧]𝜓 ↔ [(℩𝑥𝜑) / 𝑧]𝜓)) | ||||||||||||||||||||||||||||||||
| Theorem | sbiota1 45512 | Theorem *14.25 in [WhiteheadRussell] p. 192. (Contributed by Andrew Salmon, 12-Jul-2011.) | ||||||||||||||||||||||||||||||
| ⊢ (∃!𝑥𝜑 → (∀𝑥(𝜑 → 𝜓) ↔ [(℩𝑥𝜑) / 𝑥]𝜓)) | ||||||||||||||||||||||||||||||||
| Theorem | sbaniota 45513 | Theorem *14.26 in [WhiteheadRussell] p. 192. (Contributed by Andrew Salmon, 12-Jul-2011.) | ||||||||||||||||||||||||||||||
| ⊢ (∃!𝑥𝜑 → (∃𝑥(𝜑 ∧ 𝜓) ↔ [(℩𝑥𝜑) / 𝑥]𝜓)) | ||||||||||||||||||||||||||||||||
| Theorem | iotasbcq 45514 | Theorem *14.272 in [WhiteheadRussell] p. 193. (Contributed by Andrew Salmon, 11-Jul-2011.) | ||||||||||||||||||||||||||||||
| ⊢ (∀𝑥(𝜑 ↔ 𝜓) → ([(℩𝑥𝜑) / 𝑦]𝜒 ↔ [(℩𝑥𝜓) / 𝑦]𝜒)) | ||||||||||||||||||||||||||||||||
| Theorem | elnev 45515* | Any set that contains one element less than the universe is not equal to it. (Contributed by Andrew Salmon, 16-Jun-2011.) | ||||||||||||||||||||||||||||||
| ⊢ (𝐴 ∈ V ↔ {𝑥 ∣ ¬ 𝑥 = 𝐴} ≠ V) | ||||||||||||||||||||||||||||||||
| Theorem | rusbcALT 45516 | A version of Russell's paradox which is proven using proper substitution. (Contributed by Andrew Salmon, 18-Jun-2011.) (New usage is discouraged.) (Proof modification is discouraged.) | ||||||||||||||||||||||||||||||
| ⊢ {𝑥 ∣ 𝑥 ∉ 𝑥} ∉ V | ||||||||||||||||||||||||||||||||
| Theorem | compeq 45517* | Equality between two ways of saying "the complement of 𝐴". (Contributed by Andrew Salmon, 15-Jul-2011.) | ||||||||||||||||||||||||||||||
| ⊢ (V ∖ 𝐴) = {𝑥 ∣ ¬ 𝑥 ∈ 𝐴} | ||||||||||||||||||||||||||||||||
| Theorem | compne 45518 | The complement of 𝐴 is not equal to 𝐴. (Contributed by Andrew Salmon, 15-Jul-2011.) (Proof shortened by BJ, 11-Nov-2021.) | ||||||||||||||||||||||||||||||
| ⊢ (V ∖ 𝐴) ≠ 𝐴 | ||||||||||||||||||||||||||||||||
| Theorem | compab 45519 | Two ways of saying "the complement of a class abstraction". (Contributed by Andrew Salmon, 15-Jul-2011.) (Proof shortened by Mario Carneiro, 11-Dec-2016.) | ||||||||||||||||||||||||||||||
| ⊢ (V ∖ {𝑧 ∣ 𝜑}) = {𝑧 ∣ ¬ 𝜑} | ||||||||||||||||||||||||||||||||
| Theorem | conss2 45520 | Contrapositive law for subsets. (Contributed by Andrew Salmon, 15-Jul-2011.) | ||||||||||||||||||||||||||||||
| ⊢ (𝐴 ⊆ (V ∖ 𝐵) ↔ 𝐵 ⊆ (V ∖ 𝐴)) | ||||||||||||||||||||||||||||||||
| Theorem | conss1 45521 | Contrapositive law for subsets. (Contributed by Andrew Salmon, 15-Jul-2011.) | ||||||||||||||||||||||||||||||
| ⊢ ((V ∖ 𝐴) ⊆ 𝐵 ↔ (V ∖ 𝐵) ⊆ 𝐴) | ||||||||||||||||||||||||||||||||
| Theorem | ralbidar 45522 | More general form of ralbida 3273. (Contributed by Andrew Salmon, 25-Jul-2011.) | ||||||||||||||||||||||||||||||
| ⊢ (𝜑 → ∀𝑥 ∈ 𝐴 𝜑) & ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → (𝜓 ↔ 𝜒)) ⇒ ⊢ (𝜑 → (∀𝑥 ∈ 𝐴 𝜓 ↔ ∀𝑥 ∈ 𝐴 𝜒)) | ||||||||||||||||||||||||||||||||
| Theorem | rexbidar 45523 | More general form of rexbida 3274. (Contributed by Andrew Salmon, 25-Jul-2011.) | ||||||||||||||||||||||||||||||
| ⊢ (𝜑 → ∀𝑥 ∈ 𝐴 𝜑) & ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → (𝜓 ↔ 𝜒)) ⇒ ⊢ (𝜑 → (∃𝑥 ∈ 𝐴 𝜓 ↔ ∃𝑥 ∈ 𝐴 𝜒)) | ||||||||||||||||||||||||||||||||
| Theorem | dropab1 45524 | Theorem to aid use of the distinctor reduction theorem with ordered pair class abstraction. (Contributed by Andrew Salmon, 25-Jul-2011.) | ||||||||||||||||||||||||||||||
| ⊢ (∀𝑥 𝑥 = 𝑦 → {〈𝑥, 𝑧〉 ∣ 𝜑} = {〈𝑦, 𝑧〉 ∣ 𝜑}) | ||||||||||||||||||||||||||||||||
| Theorem | dropab2 45525 | Theorem to aid use of the distinctor reduction theorem with ordered pair class abstraction. (Contributed by Andrew Salmon, 25-Jul-2011.) | ||||||||||||||||||||||||||||||
| ⊢ (∀𝑥 𝑥 = 𝑦 → {〈𝑧, 𝑥〉 ∣ 𝜑} = {〈𝑧, 𝑦〉 ∣ 𝜑}) | ||||||||||||||||||||||||||||||||
| Theorem | ipo0 45526 | If the identity relation partially orders any class, then that class is the null class. (Contributed by Andrew Salmon, 25-Jul-2011.) | ||||||||||||||||||||||||||||||
| ⊢ ( I Po 𝐴 ↔ 𝐴 = ∅) | ||||||||||||||||||||||||||||||||
| Theorem | ifr0 45527 | A class that is founded by the identity relation is null. (Contributed by Andrew Salmon, 25-Jul-2011.) | ||||||||||||||||||||||||||||||
| ⊢ ( I Fr 𝐴 ↔ 𝐴 = ∅) | ||||||||||||||||||||||||||||||||
| Theorem | fvsb 45528* | Explicit substitution of a value of a function into a wff. (Contributed by Andrew Salmon, 1-Aug-2011.) | ||||||||||||||||||||||||||||||
| ⊢ (∃!𝑦 𝐴𝐹𝑦 → ([(𝐹‘𝐴) / 𝑥]𝜑 ↔ ∃𝑥(∀𝑦(𝐴𝐹𝑦 ↔ 𝑦 = 𝑥) ∧ 𝜑))) | ||||||||||||||||||||||||||||||||
| Theorem | fveqsb 45529* | Implicit substitution of a value of a function into a wff. (Contributed by Andrew Salmon, 1-Aug-2011.) | ||||||||||||||||||||||||||||||
| ⊢ (𝑥 = (𝐹‘𝐴) → (𝜑 ↔ 𝜓)) & ⊢ Ⅎ𝑥𝜓 ⇒ ⊢ (∃!𝑦 𝐴𝐹𝑦 → (𝜓 ↔ ∃𝑥(∀𝑦(𝐴𝐹𝑦 ↔ 𝑦 = 𝑥) ∧ 𝜑))) | ||||||||||||||||||||||||||||||||
| Theorem | xpexb 45530 | A Cartesian product exists iff its converse does. Corollary 6.9(1) in [TakeutiZaring] p. 26. (Contributed by Andrew Salmon, 13-Nov-2011.) | ||||||||||||||||||||||||||||||
| ⊢ ((𝐴 × 𝐵) ∈ V ↔ (𝐵 × 𝐴) ∈ V) | ||||||||||||||||||||||||||||||||
| Theorem | trelpss 45531 | An element of a transitive set is a proper subset of it. Theorem 7.2 in [TakeutiZaring] p. 35. Unlike tz7.2 5633, ax-reg 9590 is required for its proof. (Contributed by Andrew Salmon, 13-Nov-2011.) | ||||||||||||||||||||||||||||||
| ⊢ ((Tr 𝐴 ∧ 𝐵 ∈ 𝐴) → 𝐵 ⊊ 𝐴) | ||||||||||||||||||||||||||||||||
| Theorem | addcomgi 45532 | Generalization of commutative law for addition. Simplifies proofs dealing with vectors. However, it is dependent on our particular definition of ordered pair. (Contributed by Andrew Salmon, 28-Jan-2012.) (Revised by Mario Carneiro, 6-May-2015.) | ||||||||||||||||||||||||||||||
| ⊢ (𝐴 + 𝐵) = (𝐵 + 𝐴) | ||||||||||||||||||||||||||||||||
| Syntax | cplusr 45533 | Introduce the operation of vector addition. | ||||||||||||||||||||||||||||||
| class +𝑟 | ||||||||||||||||||||||||||||||||
| Syntax | cminusr 45534 | Introduce the operation of vector subtraction. | ||||||||||||||||||||||||||||||
| class -𝑟 | ||||||||||||||||||||||||||||||||
| Syntax | ctimesr 45535 | Introduce the operation of scalar multiplication. | ||||||||||||||||||||||||||||||
| class .𝑣 | ||||||||||||||||||||||||||||||||
| Syntax | cptdfc 45536 | PtDf is a predicate that is crucial for the definition of lines as well as proving a number of important theorems. | ||||||||||||||||||||||||||||||
| class PtDf(𝐴, 𝐵) | ||||||||||||||||||||||||||||||||
| Syntax | crr3c 45537 | RR3 is a class. | ||||||||||||||||||||||||||||||
| class RR3 | ||||||||||||||||||||||||||||||||
| Syntax | cline3 45538 | line3 is a class. | ||||||||||||||||||||||||||||||
| class line3 | ||||||||||||||||||||||||||||||||
| Definition | df-addr 45539* | Define the operation of vector addition. (Contributed by Andrew Salmon, 27-Jan-2012.) | ||||||||||||||||||||||||||||||
| ⊢ +𝑟 = (𝑥 ∈ V, 𝑦 ∈ V ↦ (𝑣 ∈ ℝ ↦ ((𝑥‘𝑣) + (𝑦‘𝑣)))) | ||||||||||||||||||||||||||||||||
| Definition | df-subr 45540* | Define the operation of vector subtraction. (Contributed by Andrew Salmon, 27-Jan-2012.) | ||||||||||||||||||||||||||||||
| ⊢ -𝑟 = (𝑥 ∈ V, 𝑦 ∈ V ↦ (𝑣 ∈ ℝ ↦ ((𝑥‘𝑣) − (𝑦‘𝑣)))) | ||||||||||||||||||||||||||||||||
| Definition | df-mulv 45541* | Define the operation of scalar multiplication. (Contributed by Andrew Salmon, 27-Jan-2012.) | ||||||||||||||||||||||||||||||
| ⊢ .𝑣 = (𝑥 ∈ V, 𝑦 ∈ V ↦ (𝑣 ∈ ℝ ↦ (𝑥 · (𝑦‘𝑣)))) | ||||||||||||||||||||||||||||||||
| Theorem | addrval 45542* | Value of the operation of vector addition. (Contributed by Andrew Salmon, 27-Jan-2012.) | ||||||||||||||||||||||||||||||
| ⊢ ((𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐷) → (𝐴+𝑟𝐵) = (𝑣 ∈ ℝ ↦ ((𝐴‘𝑣) + (𝐵‘𝑣)))) | ||||||||||||||||||||||||||||||||
| Theorem | subrval 45543* | Value of the operation of vector subtraction. (Contributed by Andrew Salmon, 27-Jan-2012.) | ||||||||||||||||||||||||||||||
| ⊢ ((𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐷) → (𝐴-𝑟𝐵) = (𝑣 ∈ ℝ ↦ ((𝐴‘𝑣) − (𝐵‘𝑣)))) | ||||||||||||||||||||||||||||||||
| Theorem | mulvval 45544* | Value of the operation of scalar multiplication. (Contributed by Andrew Salmon, 27-Jan-2012.) | ||||||||||||||||||||||||||||||
| ⊢ ((𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐷) → (𝐴.𝑣𝐵) = (𝑣 ∈ ℝ ↦ (𝐴 · (𝐵‘𝑣)))) | ||||||||||||||||||||||||||||||||
| Theorem | addrfv 45545 | Vector addition at a value. The operation takes each vector 𝐴 and 𝐵 and forms a new vector whose values are the sum of each of the values of 𝐴 and 𝐵. (Contributed by Andrew Salmon, 27-Jan-2012.) | ||||||||||||||||||||||||||||||
| ⊢ ((𝐴 ∈ 𝐸 ∧ 𝐵 ∈ 𝐷 ∧ 𝐶 ∈ ℝ) → ((𝐴+𝑟𝐵)‘𝐶) = ((𝐴‘𝐶) + (𝐵‘𝐶))) | ||||||||||||||||||||||||||||||||
| Theorem | subrfv 45546 | Vector subtraction at a value. (Contributed by Andrew Salmon, 27-Jan-2012.) | ||||||||||||||||||||||||||||||
| ⊢ ((𝐴 ∈ 𝐸 ∧ 𝐵 ∈ 𝐷 ∧ 𝐶 ∈ ℝ) → ((𝐴-𝑟𝐵)‘𝐶) = ((𝐴‘𝐶) − (𝐵‘𝐶))) | ||||||||||||||||||||||||||||||||
| Theorem | mulvfv 45547 | Scalar multiplication at a value. (Contributed by Andrew Salmon, 27-Jan-2012.) | ||||||||||||||||||||||||||||||
| ⊢ ((𝐴 ∈ 𝐸 ∧ 𝐵 ∈ 𝐷 ∧ 𝐶 ∈ ℝ) → ((𝐴.𝑣𝐵)‘𝐶) = (𝐴 · (𝐵‘𝐶))) | ||||||||||||||||||||||||||||||||
| Theorem | addrfn 45548 | Vector addition produces a function. (Contributed by Andrew Salmon, 27-Jan-2012.) | ||||||||||||||||||||||||||||||
| ⊢ ((𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐷) → (𝐴+𝑟𝐵) Fn ℝ) | ||||||||||||||||||||||||||||||||
| Theorem | subrfn 45549 | Vector subtraction produces a function. (Contributed by Andrew Salmon, 27-Jan-2012.) | ||||||||||||||||||||||||||||||
| ⊢ ((𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐷) → (𝐴-𝑟𝐵) Fn ℝ) | ||||||||||||||||||||||||||||||||
| Theorem | mulvfn 45550 | Scalar multiplication producees a function. (Contributed by Andrew Salmon, 27-Jan-2012.) | ||||||||||||||||||||||||||||||
| ⊢ ((𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐷) → (𝐴.𝑣𝐵) Fn ℝ) | ||||||||||||||||||||||||||||||||
| Theorem | addrcom 45551 | Vector addition is commutative. (Contributed by Andrew Salmon, 28-Jan-2012.) | ||||||||||||||||||||||||||||||
| ⊢ ((𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐷) → (𝐴+𝑟𝐵) = (𝐵+𝑟𝐴)) | ||||||||||||||||||||||||||||||||
| Definition | df-ptdf 45552* | Define the predicate PtDf, which is a utility definition used to shorten definitions and simplify proofs. (Contributed by Andrew Salmon, 15-Jul-2012.) | ||||||||||||||||||||||||||||||
| ⊢ PtDf(𝐴, 𝐵) = (𝑥 ∈ ℝ ↦ (((𝑥.𝑣(𝐵-𝑟𝐴)) +𝑣 𝐴) “ {1, 2, 3})) | ||||||||||||||||||||||||||||||||
| Definition | df-rr3 45553 | Define the set of all points RR3. We define each point 𝐴 as a function to allow the use of vector addition and subtraction as well as scalar multiplication in our proofs. (Contributed by Andrew Salmon, 15-Jul-2012.) | ||||||||||||||||||||||||||||||
| ⊢ RR3 = (ℝ ↑m {1, 2, 3}) | ||||||||||||||||||||||||||||||||
| Definition | df-line3 45554* | Define the set of all lines. A line is an infinite subset of RR3 that satisfies a PtDf property. (Contributed by Andrew Salmon, 15-Jul-2012.) | ||||||||||||||||||||||||||||||
| ⊢ line3 = {𝑥 ∈ 𝒫 RR3 ∣ (2o ≼ 𝑥 ∧ ∀𝑦 ∈ 𝑥 ∀𝑧 ∈ 𝑥 (𝑧 ≠ 𝑦 → ran PtDf(𝑦, 𝑧) = 𝑥))} | ||||||||||||||||||||||||||||||||
We are sad to report the passing of long-time contributor Alan Sare (Nov. 9, 1954 - Mar. 23, 2019). Alan's first contribution to Metamath was a shorter proof for tfrlem8 8396 in 2008. He developed a tool called "completeusersproof" that assists developing proofs using his "virtual deduction" method: https://us.metamath.org/other.html#completeusersproof 8396. His virtual deduction method is explained in the comment for wvd1 45646. Below are some excerpts from his first emails to NM in 2007: ...I have been interested in proving set theory theorems for many years for mental exercise. I enjoy it. I have used a book by Martin Zuckerman. It is informal. I am interested in completely and perfectly proving theorems. Mr. Zuckerman leaves out most of the steps of a proof, of course, like most authors do, as you have noted. A complete proof for higher theorems would require a volume of writing similar to the Metamath documents. So I am frustrated when I am not capable of constructing a proof and Zuckerman leaves out steps I do not understand. I could search for the steps in other texts, but I don't do that too much. Metamath may be the answer for me.... ...If we go beyond mathematics, I believe that it is possible to write down all human knowledge in a way similar to the way you have explicated large areas of mathematics. Of course, that would be a much, much more difficult job. For example, it is possible to take a hard science like physics, construct axioms based on experimental results, and to cast all of physics into a collection of axioms and theorems. Maybe this has already been attempted, although I am not familiar with it. When one then moves on to the soft sciences such as social science, this job gets much more difficult. The key is: All human thought consists of logical operations on abstract objects. Usually, these logical operations are done informally. There is no reason why one cannot take any subject and explicate it and take it down to the indivisible postulates in a formal rigorous way.... ...When I read a math book or an engineering book I come across something I don't understand and I am compelled to understand it. But, often it is hopeless. I don't have the time. Or, I would have to read the same thing by multiple authors in the hope that different authors would give parts of the working proof that others have omitted. It is very inefficient. Because I have always been inclined to "get to the bottom" for a 100% fully understood proof.... | ||||||||||||||||||||||||||||||||
| Theorem | idiALT 45555 | Placeholder for idi 1. Though unnecessary, this theorem is sometimes used in proofs in this mathbox for pedagogical purposes. (Contributed by Alan Sare, 31-Dec-2011.) (Proof modification is discouraged.) (New usage is discouraged.) | ||||||||||||||||||||||||||||||
| ⊢ 𝜑 ⇒ ⊢ 𝜑 | ||||||||||||||||||||||||||||||||
| Theorem | exbir 45556 | Exportation implication also converting the consequent from a biconditional to an implication. Derived automatically from exbirVD 45929. (Contributed by Alan Sare, 31-Dec-2011.) | ||||||||||||||||||||||||||||||
| ⊢ (((𝜑 ∧ 𝜓) → (𝜒 ↔ 𝜃)) → (𝜑 → (𝜓 → (𝜃 → 𝜒)))) | ||||||||||||||||||||||||||||||||
| Theorem | 3impexpbicom 45557 | Version of 3impexp 1377 where in addition the consequent is commuted. (Contributed by Alan Sare, 31-Dec-2011.) | ||||||||||||||||||||||||||||||
| ⊢ (((𝜑 ∧ 𝜓 ∧ 𝜒) → (𝜃 ↔ 𝜏)) ↔ (𝜑 → (𝜓 → (𝜒 → (𝜏 ↔ 𝜃))))) | ||||||||||||||||||||||||||||||||
| Theorem | 3impexpbicomi 45558 | Inference associated with 3impexpbicom 45557. Derived automatically from 3impexpbicomiVD 45934. (Contributed by Alan Sare, 31-Dec-2011.) | ||||||||||||||||||||||||||||||
| ⊢ ((𝜑 ∧ 𝜓 ∧ 𝜒) → (𝜃 ↔ 𝜏)) ⇒ ⊢ (𝜑 → (𝜓 → (𝜒 → (𝜏 ↔ 𝜃)))) | ||||||||||||||||||||||||||||||||
| Theorem | bi1imp 45559 | Importation inference similar to imp 412, except the outermost implication of the hypothesis is a biconditional. (Contributed by Alan Sare, 6-Nov-2017.) | ||||||||||||||||||||||||||||||
| ⊢ (𝜑 ↔ (𝜓 → 𝜒)) ⇒ ⊢ ((𝜑 ∧ 𝜓) → 𝜒) | ||||||||||||||||||||||||||||||||
| Theorem | bi2imp 45560 | Importation inference similar to imp 412, except both implications of the hypothesis are biconditionals. (Contributed by Alan Sare, 6-Nov-2017.) | ||||||||||||||||||||||||||||||
| ⊢ (𝜑 ↔ (𝜓 ↔ 𝜒)) ⇒ ⊢ ((𝜑 ∧ 𝜓) → 𝜒) | ||||||||||||||||||||||||||||||||
| Theorem | bi3impb 45561 | Similar to 3impb 1132 with implication in hypothesis replaced by biconditional. (Contributed by Alan Sare, 6-Nov-2017.) | ||||||||||||||||||||||||||||||
| ⊢ ((𝜑 ∧ (𝜓 ∧ 𝜒)) ↔ 𝜃) ⇒ ⊢ ((𝜑 ∧ 𝜓 ∧ 𝜒) → 𝜃) | ||||||||||||||||||||||||||||||||
| Theorem | bi3impa 45562 | Similar to 3impa 1127 with implication in hypothesis replaced by biconditional. (Contributed by Alan Sare, 6-Nov-2017.) | ||||||||||||||||||||||||||||||
| ⊢ (((𝜑 ∧ 𝜓) ∧ 𝜒) ↔ 𝜃) ⇒ ⊢ ((𝜑 ∧ 𝜓 ∧ 𝜒) → 𝜃) | ||||||||||||||||||||||||||||||||
| Theorem | bi23impib 45563 | 3impib 1134 with the inner implication of the hypothesis a biconditional. (Contributed by Alan Sare, 6-Nov-2017.) | ||||||||||||||||||||||||||||||
| ⊢ (𝜑 → ((𝜓 ∧ 𝜒) ↔ 𝜃)) ⇒ ⊢ ((𝜑 ∧ 𝜓 ∧ 𝜒) → 𝜃) | ||||||||||||||||||||||||||||||||
| Theorem | bi13impib 45564 | 3impib 1134 with the outer implication of the hypothesis a biconditional. (Contributed by Alan Sare, 6-Nov-2017.) | ||||||||||||||||||||||||||||||
| ⊢ (𝜑 ↔ ((𝜓 ∧ 𝜒) → 𝜃)) ⇒ ⊢ ((𝜑 ∧ 𝜓 ∧ 𝜒) → 𝜃) | ||||||||||||||||||||||||||||||||
| Theorem | bi123impib 45565 | 3impib 1134 with the implications of the hypothesis biconditionals. (Contributed by Alan Sare, 6-Nov-2017.) | ||||||||||||||||||||||||||||||
| ⊢ (𝜑 ↔ ((𝜓 ∧ 𝜒) ↔ 𝜃)) ⇒ ⊢ ((𝜑 ∧ 𝜓 ∧ 𝜒) → 𝜃) | ||||||||||||||||||||||||||||||||
| Theorem | bi13impia 45566 | 3impia 1135 with the outer implication of the hypothesis a biconditional. (Contributed by Alan Sare, 6-Nov-2017.) | ||||||||||||||||||||||||||||||
| ⊢ ((𝜑 ∧ 𝜓) ↔ (𝜒 → 𝜃)) ⇒ ⊢ ((𝜑 ∧ 𝜓 ∧ 𝜒) → 𝜃) | ||||||||||||||||||||||||||||||||
| Theorem | bi123impia 45567 | 3impia 1135 with the implications of the hypothesis biconditionals. (Contributed by Alan Sare, 6-Nov-2017.) | ||||||||||||||||||||||||||||||
| ⊢ ((𝜑 ∧ 𝜓) ↔ (𝜒 ↔ 𝜃)) ⇒ ⊢ ((𝜑 ∧ 𝜓 ∧ 𝜒) → 𝜃) | ||||||||||||||||||||||||||||||||
| Theorem | bi33imp12 45568 | 3imp 1128 with innermost implication of the hypothesis a biconditional. (Contributed by Alan Sare, 6-Nov-2017.) | ||||||||||||||||||||||||||||||
| ⊢ (𝜑 → (𝜓 → (𝜒 ↔ 𝜃))) ⇒ ⊢ ((𝜑 ∧ 𝜓 ∧ 𝜒) → 𝜃) | ||||||||||||||||||||||||||||||||
| Theorem | bi13imp23 45569 | 3imp 1128 with outermost implication of the hypothesis a biconditional. (Contributed by Alan Sare, 6-Nov-2017.) | ||||||||||||||||||||||||||||||
| ⊢ (𝜑 ↔ (𝜓 → (𝜒 → 𝜃))) ⇒ ⊢ ((𝜑 ∧ 𝜓 ∧ 𝜒) → 𝜃) | ||||||||||||||||||||||||||||||||
| Theorem | bi13imp2 45570 | Similar to 3imp 1128 except the outermost and innermost implications are biconditionals. (Contributed by Alan Sare, 6-Nov-2017.) | ||||||||||||||||||||||||||||||
| ⊢ (𝜑 ↔ (𝜓 → (𝜒 ↔ 𝜃))) ⇒ ⊢ ((𝜑 ∧ 𝜓 ∧ 𝜒) → 𝜃) | ||||||||||||||||||||||||||||||||
| Theorem | bi12imp3 45571 | Similar to 3imp 1128 except all but innermost implication are biconditionals. (Contributed by Alan Sare, 6-Nov-2017.) | ||||||||||||||||||||||||||||||
| ⊢ (𝜑 ↔ (𝜓 ↔ (𝜒 → 𝜃))) ⇒ ⊢ ((𝜑 ∧ 𝜓 ∧ 𝜒) → 𝜃) | ||||||||||||||||||||||||||||||||
| Theorem | bi23imp1 45572 | Similar to 3imp 1128 except all but outermost implication are biconditionals. (Contributed by Alan Sare, 6-Nov-2017.) | ||||||||||||||||||||||||||||||
| ⊢ (𝜑 → (𝜓 ↔ (𝜒 ↔ 𝜃))) ⇒ ⊢ ((𝜑 ∧ 𝜓 ∧ 𝜒) → 𝜃) | ||||||||||||||||||||||||||||||||
| Theorem | bi123imp0 45573 | Similar to 3imp 1128 except all implications are biconditionals. (Contributed by Alan Sare, 6-Nov-2017.) | ||||||||||||||||||||||||||||||
| ⊢ (𝜑 ↔ (𝜓 ↔ (𝜒 ↔ 𝜃))) ⇒ ⊢ ((𝜑 ∧ 𝜓 ∧ 𝜒) → 𝜃) | ||||||||||||||||||||||||||||||||
| Theorem | 4animp1 45574 | A single hypothesis unification deduction with an assertion which is an implication with a 4-right-nested conjunction antecedent. (Contributed by Alan Sare, 30-May-2018.) | ||||||||||||||||||||||||||||||
| ⊢ ((𝜑 ∧ 𝜓 ∧ 𝜒) → (𝜏 ↔ 𝜃)) ⇒ ⊢ ((((𝜑 ∧ 𝜓) ∧ 𝜒) ∧ 𝜃) → 𝜏) | ||||||||||||||||||||||||||||||||
| Theorem | 4an31 45575 | A rearrangement of conjuncts for a 4-right-nested conjunction. (Contributed by Alan Sare, 30-May-2018.) | ||||||||||||||||||||||||||||||
| ⊢ ((((𝜒 ∧ 𝜓) ∧ 𝜑) ∧ 𝜃) → 𝜏) ⇒ ⊢ ((((𝜑 ∧ 𝜓) ∧ 𝜒) ∧ 𝜃) → 𝜏) | ||||||||||||||||||||||||||||||||
| Theorem | 4an4132 45576 | A rearrangement of conjuncts for a 4-right-nested conjunction. (Contributed by Alan Sare, 30-May-2018.) | ||||||||||||||||||||||||||||||
| ⊢ ((((𝜃 ∧ 𝜒) ∧ 𝜓) ∧ 𝜑) → 𝜏) ⇒ ⊢ ((((𝜑 ∧ 𝜓) ∧ 𝜒) ∧ 𝜃) → 𝜏) | ||||||||||||||||||||||||||||||||
| Theorem | expcomdg 45577 | Biconditional form of expcomd 422. (Contributed by Alan Sare, 22-Jul-2012.) (New usage is discouraged.) | ||||||||||||||||||||||||||||||
| ⊢ ((𝜑 → ((𝜓 ∧ 𝜒) → 𝜃)) ↔ (𝜑 → (𝜒 → (𝜓 → 𝜃)))) | ||||||||||||||||||||||||||||||||
| Theorem | iidn3 45578 | idn3 45692 without virtual deduction connectives. Special theorem needed for the Virtual Deduction translation tool. (Contributed by Alan Sare, 23-Jul-2011.) (Proof modification is discouraged.) (New usage is discouraged.) | ||||||||||||||||||||||||||||||
| ⊢ (𝜑 → (𝜓 → (𝜒 → 𝜒))) | ||||||||||||||||||||||||||||||||
| Theorem | ee222 45579 | e222 45713 without virtual deduction connectives. Special theorem needed for the Virtual Deduction translation tool. (Contributed by Alan Sare, 7-Jul-2011.) (Proof modification is discouraged.) (New usage is discouraged.) | ||||||||||||||||||||||||||||||
| ⊢ (𝜑 → (𝜓 → 𝜒)) & ⊢ (𝜑 → (𝜓 → 𝜃)) & ⊢ (𝜑 → (𝜓 → 𝜏)) & ⊢ (𝜒 → (𝜃 → (𝜏 → 𝜂))) ⇒ ⊢ (𝜑 → (𝜓 → 𝜂)) | ||||||||||||||||||||||||||||||||
| Theorem | ee3bir 45580 | Right-biconditional form of e3 45813 without virtual deduction connectives. Special theorem needed for the Virtual Deduction translation tool. (Contributed by Alan Sare, 22-Jul-2011.) (Proof modification is discouraged.) (New usage is discouraged.) | ||||||||||||||||||||||||||||||
| ⊢ (𝜑 → (𝜓 → (𝜒 → 𝜃))) & ⊢ (𝜏 ↔ 𝜃) ⇒ ⊢ (𝜑 → (𝜓 → (𝜒 → 𝜏))) | ||||||||||||||||||||||||||||||||
| Theorem | ee13 45581 | e13 45824 without virtual deduction connectives. Special theorem needed for the Virtual Deduction translation tool. (Contributed by Alan Sare, 28-Oct-2011.) (Proof modification is discouraged.) (New usage is discouraged.) | ||||||||||||||||||||||||||||||
| ⊢ (𝜑 → 𝜓) & ⊢ (𝜑 → (𝜒 → (𝜃 → 𝜏))) & ⊢ (𝜓 → (𝜏 → 𝜂)) ⇒ ⊢ (𝜑 → (𝜒 → (𝜃 → 𝜂))) | ||||||||||||||||||||||||||||||||
| Theorem | ee121 45582 | e121 45733 without virtual deductions. (Contributed by Alan Sare, 13-Jul-2011.) (Proof modification is discouraged.) (New usage is discouraged.) | ||||||||||||||||||||||||||||||
| ⊢ (𝜑 → 𝜓) & ⊢ (𝜑 → (𝜒 → 𝜃)) & ⊢ (𝜑 → 𝜏) & ⊢ (𝜓 → (𝜃 → (𝜏 → 𝜂))) ⇒ ⊢ (𝜑 → (𝜒 → 𝜂)) | ||||||||||||||||||||||||||||||||
| Theorem | ee122 45583 | e122 45730 without virtual deductions. (Contributed by Alan Sare, 13-Jul-2011.) (Proof modification is discouraged.) (New usage is discouraged.) | ||||||||||||||||||||||||||||||
| ⊢ (𝜑 → 𝜓) & ⊢ (𝜑 → (𝜒 → 𝜃)) & ⊢ (𝜑 → (𝜒 → 𝜏)) & ⊢ (𝜓 → (𝜃 → (𝜏 → 𝜂))) ⇒ ⊢ (𝜑 → (𝜒 → 𝜂)) | ||||||||||||||||||||||||||||||||
| Theorem | ee333 45584 | e333 45809 without virtual deductions. (Contributed by Alan Sare, 17-Jul-2011.) (Proof modification is discouraged.) (New usage is discouraged.) | ||||||||||||||||||||||||||||||
| ⊢ (𝜑 → (𝜓 → (𝜒 → 𝜃))) & ⊢ (𝜑 → (𝜓 → (𝜒 → 𝜏))) & ⊢ (𝜑 → (𝜓 → (𝜒 → 𝜂))) & ⊢ (𝜃 → (𝜏 → (𝜂 → 𝜁))) ⇒ ⊢ (𝜑 → (𝜓 → (𝜒 → 𝜁))) | ||||||||||||||||||||||||||||||||
| Theorem | ee323 45585 | e323 45842 without virtual deductions. (Contributed by Alan Sare, 17-Apr-2012.) (Proof modification is discouraged.) (New usage is discouraged.) | ||||||||||||||||||||||||||||||
| ⊢ (𝜑 → (𝜓 → (𝜒 → 𝜃))) & ⊢ (𝜑 → (𝜓 → 𝜏)) & ⊢ (𝜑 → (𝜓 → (𝜒 → 𝜂))) & ⊢ (𝜃 → (𝜏 → (𝜂 → 𝜁))) ⇒ ⊢ (𝜑 → (𝜓 → (𝜒 → 𝜁))) | ||||||||||||||||||||||||||||||||
| Theorem | 3ornot23 45586 | If the second and third disjuncts of a true triple disjunction are false, then the first disjunct is true. Automatically derived from 3ornot23VD 45923. (Contributed by Alan Sare, 31-Dec-2011.) (Proof modification is discouraged.) (New usage is discouraged.) | ||||||||||||||||||||||||||||||
| ⊢ ((¬ 𝜑 ∧ ¬ 𝜓) → ((𝜒 ∨ 𝜑 ∨ 𝜓) → 𝜒)) | ||||||||||||||||||||||||||||||||
| Theorem | orbi1r 45587 | orbi1 931 with order of disjuncts reversed. Derived from orbi1rVD 45924. (Contributed by Alan Sare, 31-Dec-2011.) (Proof modification is discouraged.) (New usage is discouraged.) | ||||||||||||||||||||||||||||||
| ⊢ ((𝜑 ↔ 𝜓) → ((𝜒 ∨ 𝜑) ↔ (𝜒 ∨ 𝜓))) | ||||||||||||||||||||||||||||||||
| Theorem | 3orbi123 45588 | pm4.39 992 with a 3-conjunct antecedent. This proof is 3orbi123VD 45926 automatically translated and minimized. (Contributed by Alan Sare, 31-Dec-2011.) (Proof modification is discouraged.) (New usage is discouraged.) | ||||||||||||||||||||||||||||||
| ⊢ (((𝜑 ↔ 𝜓) ∧ (𝜒 ↔ 𝜃) ∧ (𝜏 ↔ 𝜂)) → ((𝜑 ∨ 𝜒 ∨ 𝜏) ↔ (𝜓 ∨ 𝜃 ∨ 𝜂))) | ||||||||||||||||||||||||||||||||
| Theorem | syl5imp 45589 | Closed form of syl5 35. Derived automatically from syl5impVD 45939. (Contributed by Alan Sare, 31-Dec-2011.) (Proof modification is discouraged.) (New usage is discouraged.) | ||||||||||||||||||||||||||||||
| ⊢ ((𝜑 → (𝜓 → 𝜒)) → ((𝜃 → 𝜓) → (𝜑 → (𝜃 → 𝜒)))) | ||||||||||||||||||||||||||||||||
| Theorem | impexpd 45590 |
The following User's Proof is a Virtual Deduction proof completed
automatically by the tools program completeusersproof.cmd, which invokes
Mel L. O'Cat's mmj2 and Norm Megill's Metamath Proof Assistant. After the
User's Proof was completed, it was minimized. The completed User's Proof
before minimization is not shown. (Contributed by Alan Sare,
18-Mar-2012.) (Proof modification is discouraged.)
(New usage is discouraged.)
| ||||||||||||||||||||||||||||||
| ⊢ ((𝜑 → ((𝜓 ∧ 𝜒) → 𝜃)) ↔ (𝜑 → (𝜓 → (𝜒 → 𝜃)))) | ||||||||||||||||||||||||||||||||
| Theorem | com3rgbi 45591 |
The following User's Proof is a Virtual Deduction proof completed
automatically by the tools program completeusersproof.cmd, which invokes
Mel L. O'Cat's mmj2 and Norm Megill's Metamath Proof Assistant. The
completed Virtual Deduction Proof (not shown) was minimized. The
minimized proof is shown.
(Contributed by Alan Sare, 18-Mar-2012.)
(Proof modification is discouraged.) (New usage is discouraged.)
| ||||||||||||||||||||||||||||||
| ⊢ ((𝜑 → (𝜓 → (𝜒 → 𝜃))) ↔ (𝜒 → (𝜑 → (𝜓 → 𝜃)))) | ||||||||||||||||||||||||||||||||
| Theorem | impexpdcom 45592 |
The following User's Proof is a Virtual Deduction proof completed
automatically by the tools program completeusersproof.cmd, which invokes
Mel L. O'Cat's mmj2 and Norm Megill's Metamath Proof Assistant. The
completed Virtual Deduction Proof (not shown) was minimized. The
minimized proof is shown. (Contributed by Alan Sare, 18-Mar-2012.)
(Proof modification is discouraged.) (New usage is discouraged.)
| ||||||||||||||||||||||||||||||
| ⊢ ((𝜑 → ((𝜓 ∧ 𝜒) → 𝜃)) ↔ (𝜓 → (𝜒 → (𝜑 → 𝜃)))) | ||||||||||||||||||||||||||||||||
| Theorem | ee1111 45593 |
Non-virtual deduction form of e1111 45752. (Contributed by Alan Sare,
18-Mar-2012.)
(Proof modification is discouraged.) (New usage is discouraged.)
The following User's Proof is a Virtual Deduction proof
completed automatically by the tools program completeusersproof.cmd,
which invokes Mel L. O'Cat's mmj2 and Norm Megill's Metamath Proof
Assistant. The completed Virtual Deduction Proof (not shown) was
minimized. The minimized proof is shown.
| ||||||||||||||||||||||||||||||
| ⊢ (𝜑 → 𝜓) & ⊢ (𝜑 → 𝜒) & ⊢ (𝜑 → 𝜃) & ⊢ (𝜑 → 𝜏) & ⊢ (𝜓 → (𝜒 → (𝜃 → (𝜏 → 𝜂)))) ⇒ ⊢ (𝜑 → 𝜂) | ||||||||||||||||||||||||||||||||
| Theorem | pm2.43bgbi 45594 |
Logical equivalence of a 2-left-nested implication and a 1-left-nested
implicated
when two antecedents of the former implication are identical.
(Contributed by Alan Sare, 18-Mar-2012.)
(Proof modification is discouraged.) (New usage is discouraged.)
The following User's Proof is a Virtual Deduction proof completed
automatically by the tools program completeusersproof.cmd, which invokes
Mel L. O'Cat's mmj2 and Norm Megill's Metamath Proof Assistant. The
completed Virtual
Deduction Proof (not shown) was minimized. The minimized proof is
shown.
| ||||||||||||||||||||||||||||||
| ⊢ ((𝜑 → (𝜓 → (𝜑 → 𝜒))) ↔ (𝜓 → (𝜑 → 𝜒))) | ||||||||||||||||||||||||||||||||
| Theorem | pm2.43cbi 45595 |
Logical equivalence of a 3-left-nested implication and a 2-left-nested
implicated when two antecedents of the former implication are identical.
(Contributed by Alan Sare, 18-Mar-2012.)
(Proof modification is discouraged.) (New usage is discouraged.)
The following User's Proof is
a Virtual Deduction proof completed automatically by the tools program
completeusersproof.cmd, which invokes Mel L. O'Cat's mmj2 and Norm
Megill's Metamath Proof Assistant. The completed Virtual Deduction Proof
(not shown) was minimized. The minimized proof is shown.
| ||||||||||||||||||||||||||||||
| ⊢ ((𝜑 → (𝜓 → (𝜒 → (𝜑 → 𝜃)))) ↔ (𝜓 → (𝜒 → (𝜑 → 𝜃)))) | ||||||||||||||||||||||||||||||||
| Theorem | ee233 45596 |
Non-virtual deduction form of e233 45841. (Contributed by Alan Sare,
18-Mar-2012.)
(Proof modification is discouraged.) (New usage is discouraged.)
The following User's Proof is a Virtual Deduction proof completed
automatically by the tools program completeusersproof.cmd, which invokes
Mel L. O'Cat's mmj2 and Norm Megill's Metamath Proof Assistant. The
completed Virtual
Deduction Proof (not shown) was minimized. The minimized proof is
shown.
| ||||||||||||||||||||||||||||||
| ⊢ (𝜑 → (𝜓 → 𝜒)) & ⊢ (𝜑 → (𝜓 → (𝜃 → 𝜏))) & ⊢ (𝜑 → (𝜓 → (𝜃 → 𝜂))) & ⊢ (𝜒 → (𝜏 → (𝜂 → 𝜁))) ⇒ ⊢ (𝜑 → (𝜓 → (𝜃 → 𝜁))) | ||||||||||||||||||||||||||||||||
| Theorem | imbi13 45597 | Join three logical equivalences to form equivalence of implications. imbi13 45597 is imbi13VD 45950 without virtual deductions and was automatically derived from imbi13VD 45950 using the tools program translate..without..overwriting.cmd and Metamath's minimize command. (Contributed by Alan Sare, 18-Mar-2012.) (Proof modification is discouraged.) (New usage is discouraged.) | ||||||||||||||||||||||||||||||
| ⊢ ((𝜑 ↔ 𝜓) → ((𝜒 ↔ 𝜃) → ((𝜏 ↔ 𝜂) → ((𝜑 → (𝜒 → 𝜏)) ↔ (𝜓 → (𝜃 → 𝜂)))))) | ||||||||||||||||||||||||||||||||
| Theorem | ee33 45598 |
Non-virtual deduction form of e33 45810. (Contributed by Alan Sare,
18-Mar-2012.) (Proof modification is discouraged.)
(New usage is discouraged.)
The following User's Proof is a Virtual Deduction proof
completed automatically by the tools program completeusersproof.cmd,
which invokes Mel L. O'Cat's mmj2 and Norm Megill's Metamath Proof
Assistant. The completed Virtual Deduction Proof (not shown) was
minimized. The minimized proof is shown.
| ||||||||||||||||||||||||||||||
| ⊢ (𝜑 → (𝜓 → (𝜒 → 𝜃))) & ⊢ (𝜑 → (𝜓 → (𝜒 → 𝜏))) & ⊢ (𝜃 → (𝜏 → 𝜂)) ⇒ ⊢ (𝜑 → (𝜓 → (𝜒 → 𝜂))) | ||||||||||||||||||||||||||||||||
| Theorem | con5 45599 | Biconditional contraposition variation. This proof is con5VD 45976 automatically translated and minimized. (Contributed by Alan Sare, 21-Apr-2013.) (Proof modification is discouraged.) (New usage is discouraged.) | ||||||||||||||||||||||||||||||
| ⊢ ((𝜑 ↔ ¬ 𝜓) → (¬ 𝜑 → 𝜓)) | ||||||||||||||||||||||||||||||||
| Theorem | con5i 45600 | Inference form of con5 45599. (Contributed by Alan Sare, 21-Apr-2013.) (Proof modification is discouraged.) (New usage is discouraged.) | ||||||||||||||||||||||||||||||
| ⊢ (𝜑 ↔ ¬ 𝜓) ⇒ ⊢ (¬ 𝜑 → 𝜓) | ||||||||||||||||||||||||||||||||
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