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Type | Label | Description |
---|---|---|
Statement | ||
Theorem | neeq1 3001 | Equality theorem for inequality. (Contributed by NM, 19-Nov-1994.) (Proof shortened by Wolf Lammen, 18-Nov-2019.) |
⊢ (𝐴 = 𝐵 → (𝐴 ≠ 𝐶 ↔ 𝐵 ≠ 𝐶)) | ||
Theorem | neeq2 3002 | Equality theorem for inequality. (Contributed by NM, 19-Nov-1994.) (Proof shortened by Wolf Lammen, 18-Nov-2019.) |
⊢ (𝐴 = 𝐵 → (𝐶 ≠ 𝐴 ↔ 𝐶 ≠ 𝐵)) | ||
Theorem | neeq1i 3003 | Inference for inequality. (Contributed by NM, 29-Apr-2005.) (Proof shortened by Wolf Lammen, 19-Nov-2019.) |
⊢ 𝐴 = 𝐵 ⇒ ⊢ (𝐴 ≠ 𝐶 ↔ 𝐵 ≠ 𝐶) | ||
Theorem | neeq2i 3004 | Inference for inequality. (Contributed by NM, 29-Apr-2005.) (Proof shortened by Wolf Lammen, 19-Nov-2019.) |
⊢ 𝐴 = 𝐵 ⇒ ⊢ (𝐶 ≠ 𝐴 ↔ 𝐶 ≠ 𝐵) | ||
Theorem | neeq12i 3005 | Inference for inequality. (Contributed by NM, 24-Jul-2012.) (Proof shortened by Wolf Lammen, 25-Nov-2019.) |
⊢ 𝐴 = 𝐵 & ⊢ 𝐶 = 𝐷 ⇒ ⊢ (𝐴 ≠ 𝐶 ↔ 𝐵 ≠ 𝐷) | ||
Theorem | eqnetrd 3006 | Substitution of equal classes into an inequality. (Contributed by NM, 4-Jul-2012.) |
⊢ (𝜑 → 𝐴 = 𝐵) & ⊢ (𝜑 → 𝐵 ≠ 𝐶) ⇒ ⊢ (𝜑 → 𝐴 ≠ 𝐶) | ||
Theorem | eqnetrrd 3007 | Substitution of equal classes into an inequality. (Contributed by NM, 4-Jul-2012.) |
⊢ (𝜑 → 𝐴 = 𝐵) & ⊢ (𝜑 → 𝐴 ≠ 𝐶) ⇒ ⊢ (𝜑 → 𝐵 ≠ 𝐶) | ||
Theorem | neeqtrd 3008 | Substitution of equal classes into an inequality. (Contributed by NM, 4-Jul-2012.) |
⊢ (𝜑 → 𝐴 ≠ 𝐵) & ⊢ (𝜑 → 𝐵 = 𝐶) ⇒ ⊢ (𝜑 → 𝐴 ≠ 𝐶) | ||
Theorem | eqnetri 3009 | Substitution of equal classes into an inequality. (Contributed by NM, 4-Jul-2012.) |
⊢ 𝐴 = 𝐵 & ⊢ 𝐵 ≠ 𝐶 ⇒ ⊢ 𝐴 ≠ 𝐶 | ||
Theorem | eqnetrri 3010 | Substitution of equal classes into an inequality. (Contributed by NM, 4-Jul-2012.) |
⊢ 𝐴 = 𝐵 & ⊢ 𝐴 ≠ 𝐶 ⇒ ⊢ 𝐵 ≠ 𝐶 | ||
Theorem | neeqtri 3011 | Substitution of equal classes into an inequality. (Contributed by NM, 4-Jul-2012.) |
⊢ 𝐴 ≠ 𝐵 & ⊢ 𝐵 = 𝐶 ⇒ ⊢ 𝐴 ≠ 𝐶 | ||
Theorem | neeqtrri 3012 | Substitution of equal classes into an inequality. (Contributed by NM, 4-Jul-2012.) |
⊢ 𝐴 ≠ 𝐵 & ⊢ 𝐶 = 𝐵 ⇒ ⊢ 𝐴 ≠ 𝐶 | ||
Theorem | neeqtrrd 3013 | Substitution of equal classes into an inequality. (Contributed by NM, 4-Jul-2012.) |
⊢ (𝜑 → 𝐴 ≠ 𝐵) & ⊢ (𝜑 → 𝐶 = 𝐵) ⇒ ⊢ (𝜑 → 𝐴 ≠ 𝐶) | ||
Theorem | eqnetrrid 3014 | A chained equality inference for inequality. (Contributed by NM, 6-Jun-2012.) (Proof shortened by Wolf Lammen, 19-Nov-2019.) |
⊢ 𝐵 = 𝐴 & ⊢ (𝜑 → 𝐵 ≠ 𝐶) ⇒ ⊢ (𝜑 → 𝐴 ≠ 𝐶) | ||
Theorem | 3netr3d 3015 | Substitution of equality into both sides of an inequality. (Contributed by NM, 24-Jul-2012.) (Proof shortened by Wolf Lammen, 19-Nov-2019.) |
⊢ (𝜑 → 𝐴 ≠ 𝐵) & ⊢ (𝜑 → 𝐴 = 𝐶) & ⊢ (𝜑 → 𝐵 = 𝐷) ⇒ ⊢ (𝜑 → 𝐶 ≠ 𝐷) | ||
Theorem | 3netr4d 3016 | Substitution of equality into both sides of an inequality. (Contributed by NM, 24-Jul-2012.) (Proof shortened by Wolf Lammen, 21-Nov-2019.) |
⊢ (𝜑 → 𝐴 ≠ 𝐵) & ⊢ (𝜑 → 𝐶 = 𝐴) & ⊢ (𝜑 → 𝐷 = 𝐵) ⇒ ⊢ (𝜑 → 𝐶 ≠ 𝐷) | ||
Theorem | 3netr3g 3017 | Substitution of equality into both sides of an inequality. (Contributed by NM, 24-Jul-2012.) |
⊢ (𝜑 → 𝐴 ≠ 𝐵) & ⊢ 𝐴 = 𝐶 & ⊢ 𝐵 = 𝐷 ⇒ ⊢ (𝜑 → 𝐶 ≠ 𝐷) | ||
Theorem | 3netr4g 3018 | Substitution of equality into both sides of an inequality. (Contributed by NM, 14-Jun-2012.) |
⊢ (𝜑 → 𝐴 ≠ 𝐵) & ⊢ 𝐶 = 𝐴 & ⊢ 𝐷 = 𝐵 ⇒ ⊢ (𝜑 → 𝐶 ≠ 𝐷) | ||
Theorem | nebi 3019 | Contraposition law for inequality. (Contributed by NM, 28-Dec-2008.) |
⊢ ((𝐴 = 𝐵 ↔ 𝐶 = 𝐷) ↔ (𝐴 ≠ 𝐵 ↔ 𝐶 ≠ 𝐷)) | ||
Theorem | pm13.18 3020 | Theorem *13.18 in [WhiteheadRussell] p. 178. (Contributed by Andrew Salmon, 3-Jun-2011.) (Proof shortened by Wolf Lammen, 29-Oct-2024.) |
⊢ ((𝐴 = 𝐵 ∧ 𝐴 ≠ 𝐶) → 𝐵 ≠ 𝐶) | ||
Theorem | pm13.181 3021 | Theorem *13.181 in [WhiteheadRussell] p. 178. (Contributed by Andrew Salmon, 3-Jun-2011.) (Proof shortened by Wolf Lammen, 30-Oct-2024.) |
⊢ ((𝐴 = 𝐵 ∧ 𝐵 ≠ 𝐶) → 𝐴 ≠ 𝐶) | ||
Theorem | pm13.181OLD 3022 | Obsolete version of pm13.181 3021 as of 30-Oct-2024. (Contributed by Andrew Salmon, 3-Jun-2011.) (New usage is discouraged.) (Proof modification is discouraged.) |
⊢ ((𝐴 = 𝐵 ∧ 𝐵 ≠ 𝐶) → 𝐴 ≠ 𝐶) | ||
Theorem | pm2.61ine 3023 | Inference eliminating an inequality in an antecedent. (Contributed by NM, 16-Jan-2007.) (Proof shortened by Andrew Salmon, 25-May-2011.) |
⊢ (𝐴 = 𝐵 → 𝜑) & ⊢ (𝐴 ≠ 𝐵 → 𝜑) ⇒ ⊢ 𝜑 | ||
Theorem | pm2.21ddne 3024 | A contradiction implies anything. Equality/inequality deduction form. (Contributed by David Moews, 28-Feb-2017.) |
⊢ (𝜑 → 𝐴 = 𝐵) & ⊢ (𝜑 → 𝐴 ≠ 𝐵) ⇒ ⊢ (𝜑 → 𝜓) | ||
Theorem | pm2.61ne 3025 | Deduction eliminating an inequality in an antecedent. (Contributed by NM, 24-May-2006.) (Proof shortened by Andrew Salmon, 25-May-2011.) (Proof shortened by Wolf Lammen, 25-Nov-2019.) |
⊢ (𝐴 = 𝐵 → (𝜓 ↔ 𝜒)) & ⊢ ((𝜑 ∧ 𝐴 ≠ 𝐵) → 𝜓) & ⊢ (𝜑 → 𝜒) ⇒ ⊢ (𝜑 → 𝜓) | ||
Theorem | pm2.61dne 3026 | Deduction eliminating an inequality in an antecedent. (Contributed by NM, 1-Jun-2007.) (Proof shortened by Andrew Salmon, 25-May-2011.) |
⊢ (𝜑 → (𝐴 = 𝐵 → 𝜓)) & ⊢ (𝜑 → (𝐴 ≠ 𝐵 → 𝜓)) ⇒ ⊢ (𝜑 → 𝜓) | ||
Theorem | pm2.61dane 3027 | Deduction eliminating an inequality in an antecedent. (Contributed by NM, 30-Nov-2011.) |
⊢ ((𝜑 ∧ 𝐴 = 𝐵) → 𝜓) & ⊢ ((𝜑 ∧ 𝐴 ≠ 𝐵) → 𝜓) ⇒ ⊢ (𝜑 → 𝜓) | ||
Theorem | pm2.61da2ne 3028 | Deduction eliminating two inequalities in an antecedent. (Contributed by NM, 29-May-2013.) |
⊢ ((𝜑 ∧ 𝐴 = 𝐵) → 𝜓) & ⊢ ((𝜑 ∧ 𝐶 = 𝐷) → 𝜓) & ⊢ ((𝜑 ∧ (𝐴 ≠ 𝐵 ∧ 𝐶 ≠ 𝐷)) → 𝜓) ⇒ ⊢ (𝜑 → 𝜓) | ||
Theorem | pm2.61da3ne 3029 | Deduction eliminating three inequalities in an antecedent. (Contributed by NM, 15-Jun-2013.) (Proof shortened by Wolf Lammen, 25-Nov-2019.) |
⊢ ((𝜑 ∧ 𝐴 = 𝐵) → 𝜓) & ⊢ ((𝜑 ∧ 𝐶 = 𝐷) → 𝜓) & ⊢ ((𝜑 ∧ 𝐸 = 𝐹) → 𝜓) & ⊢ ((𝜑 ∧ (𝐴 ≠ 𝐵 ∧ 𝐶 ≠ 𝐷 ∧ 𝐸 ≠ 𝐹)) → 𝜓) ⇒ ⊢ (𝜑 → 𝜓) | ||
Theorem | pm2.61iine 3030 | Equality version of pm2.61ii 183. (Contributed by Scott Fenton, 13-Jun-2013.) (Proof shortened by Wolf Lammen, 25-Nov-2019.) |
⊢ ((𝐴 ≠ 𝐶 ∧ 𝐵 ≠ 𝐷) → 𝜑) & ⊢ (𝐴 = 𝐶 → 𝜑) & ⊢ (𝐵 = 𝐷 → 𝜑) ⇒ ⊢ 𝜑 | ||
Theorem | mteqand 3031 | A modus tollens deduction for inequality. (Contributed by Steven Nguyen, 1-Jun-2023.) |
⊢ (𝜑 → 𝐶 ≠ 𝐷) & ⊢ ((𝜑 ∧ 𝐴 = 𝐵) → 𝐶 = 𝐷) ⇒ ⊢ (𝜑 → 𝐴 ≠ 𝐵) | ||
Theorem | neor 3032 | Logical OR with an equality. (Contributed by NM, 29-Apr-2007.) |
⊢ ((𝐴 = 𝐵 ∨ 𝜓) ↔ (𝐴 ≠ 𝐵 → 𝜓)) | ||
Theorem | neanior 3033 | A De Morgan's law for inequality. (Contributed by NM, 18-May-2007.) |
⊢ ((𝐴 ≠ 𝐵 ∧ 𝐶 ≠ 𝐷) ↔ ¬ (𝐴 = 𝐵 ∨ 𝐶 = 𝐷)) | ||
Theorem | ne3anior 3034 | A De Morgan's law for inequality. (Contributed by NM, 30-Sep-2013.) |
⊢ ((𝐴 ≠ 𝐵 ∧ 𝐶 ≠ 𝐷 ∧ 𝐸 ≠ 𝐹) ↔ ¬ (𝐴 = 𝐵 ∨ 𝐶 = 𝐷 ∨ 𝐸 = 𝐹)) | ||
Theorem | neorian 3035 | A De Morgan's law for inequality. (Contributed by NM, 18-May-2007.) |
⊢ ((𝐴 ≠ 𝐵 ∨ 𝐶 ≠ 𝐷) ↔ ¬ (𝐴 = 𝐵 ∧ 𝐶 = 𝐷)) | ||
Theorem | nemtbir 3036 | An inference from an inequality, related to modus tollens. (Contributed by NM, 13-Apr-2007.) |
⊢ 𝐴 ≠ 𝐵 & ⊢ (𝜑 ↔ 𝐴 = 𝐵) ⇒ ⊢ ¬ 𝜑 | ||
Theorem | nelne1 3037 | Two classes are different if they don't contain the same element. (Contributed by NM, 3-Feb-2012.) (Proof shortened by Wolf Lammen, 14-May-2023.) |
⊢ ((𝐴 ∈ 𝐵 ∧ ¬ 𝐴 ∈ 𝐶) → 𝐵 ≠ 𝐶) | ||
Theorem | nelne2 3038 | Two classes are different if they don't belong to the same class. (Contributed by NM, 25-Jun-2012.) (Proof shortened by Wolf Lammen, 14-May-2023.) |
⊢ ((𝐴 ∈ 𝐶 ∧ ¬ 𝐵 ∈ 𝐶) → 𝐴 ≠ 𝐵) | ||
Theorem | nelelne 3039 | Two classes are different if they don't belong to the same class. (Contributed by Rodolfo Medina, 17-Oct-2010.) (Proof shortened by AV, 10-May-2020.) |
⊢ (¬ 𝐴 ∈ 𝐵 → (𝐶 ∈ 𝐵 → 𝐶 ≠ 𝐴)) | ||
Theorem | neneor 3040 | If two classes are different, a third class must be different of at least one of them. (Contributed by Thierry Arnoux, 8-Aug-2020.) |
⊢ (𝐴 ≠ 𝐵 → (𝐴 ≠ 𝐶 ∨ 𝐵 ≠ 𝐶)) | ||
Theorem | nfne 3041 | Bound-variable hypothesis builder for inequality. (Contributed by NM, 10-Nov-2007.) (Revised by Mario Carneiro, 7-Oct-2016.) |
⊢ Ⅎ𝑥𝐴 & ⊢ Ⅎ𝑥𝐵 ⇒ ⊢ Ⅎ𝑥 𝐴 ≠ 𝐵 | ||
Theorem | nfned 3042 | Bound-variable hypothesis builder for inequality. (Contributed by NM, 10-Nov-2007.) (Revised by Mario Carneiro, 7-Oct-2016.) |
⊢ (𝜑 → Ⅎ𝑥𝐴) & ⊢ (𝜑 → Ⅎ𝑥𝐵) ⇒ ⊢ (𝜑 → Ⅎ𝑥 𝐴 ≠ 𝐵) | ||
Theorem | nabbib 3043 | Not equivalent wff's correspond to not equal class abstractions. (Contributed by AV, 7-Apr-2019.) (Proof shortened by Wolf Lammen, 25-Nov-2019.) Definitial form. (Revised by Wolf Lammen, 5-Mar-2025.) |
⊢ ({𝑥 ∣ 𝜑} ≠ {𝑥 ∣ 𝜓} ↔ ∃𝑥(𝜑 ↔ ¬ 𝜓)) | ||
Syntax | wnel 3044 | Extend wff notation to include negated membership. |
wff 𝐴 ∉ 𝐵 | ||
Definition | df-nel 3045 | Define negated membership. (Contributed by NM, 7-Aug-1994.) |
⊢ (𝐴 ∉ 𝐵 ↔ ¬ 𝐴 ∈ 𝐵) | ||
Theorem | neli 3046 | Inference associated with df-nel 3045. (Contributed by BJ, 7-Jul-2018.) |
⊢ 𝐴 ∉ 𝐵 ⇒ ⊢ ¬ 𝐴 ∈ 𝐵 | ||
Theorem | nelir 3047 | Inference associated with df-nel 3045. (Contributed by BJ, 7-Jul-2018.) |
⊢ ¬ 𝐴 ∈ 𝐵 ⇒ ⊢ 𝐴 ∉ 𝐵 | ||
Theorem | nelcon3d 3048 | Contrapositive law deduction for negated membership. (Contributed by AV, 28-Jan-2020.) |
⊢ (𝜑 → (𝐴 ∈ 𝐵 → 𝐶 ∈ 𝐷)) ⇒ ⊢ (𝜑 → (𝐶 ∉ 𝐷 → 𝐴 ∉ 𝐵)) | ||
Theorem | neleq12d 3049 | Equality theorem for negated membership. (Contributed by FL, 10-Aug-2016.) (Proof shortened by Wolf Lammen, 25-Nov-2019.) |
⊢ (𝜑 → 𝐴 = 𝐵) & ⊢ (𝜑 → 𝐶 = 𝐷) ⇒ ⊢ (𝜑 → (𝐴 ∉ 𝐶 ↔ 𝐵 ∉ 𝐷)) | ||
Theorem | neleq1 3050 | Equality theorem for negated membership. (Contributed by NM, 20-Nov-1994.) (Proof shortened by Wolf Lammen, 25-Nov-2019.) |
⊢ (𝐴 = 𝐵 → (𝐴 ∉ 𝐶 ↔ 𝐵 ∉ 𝐶)) | ||
Theorem | neleq2 3051 | Equality theorem for negated membership. (Contributed by NM, 20-Nov-1994.) (Proof shortened by Wolf Lammen, 25-Nov-2019.) |
⊢ (𝐴 = 𝐵 → (𝐶 ∉ 𝐴 ↔ 𝐶 ∉ 𝐵)) | ||
Theorem | nfnel 3052 | Bound-variable hypothesis builder for negated membership. (Contributed by David Abernethy, 26-Jun-2011.) (Revised by Mario Carneiro, 7-Oct-2016.) |
⊢ Ⅎ𝑥𝐴 & ⊢ Ⅎ𝑥𝐵 ⇒ ⊢ Ⅎ𝑥 𝐴 ∉ 𝐵 | ||
Theorem | nfneld 3053 | Bound-variable hypothesis builder for negated membership. (Contributed by David Abernethy, 26-Jun-2011.) (Revised by Mario Carneiro, 7-Oct-2016.) |
⊢ (𝜑 → Ⅎ𝑥𝐴) & ⊢ (𝜑 → Ⅎ𝑥𝐵) ⇒ ⊢ (𝜑 → Ⅎ𝑥 𝐴 ∉ 𝐵) | ||
Theorem | nnel 3054 | Negation of negated membership, analogous to nne 2942. (Contributed by Alexander van der Vekens, 18-Jan-2018.) (Proof shortened by Wolf Lammen, 25-Nov-2019.) |
⊢ (¬ 𝐴 ∉ 𝐵 ↔ 𝐴 ∈ 𝐵) | ||
Theorem | elnelne1 3055 | Two classes are different if they don't contain the same element. (Contributed by AV, 28-Jan-2020.) |
⊢ ((𝐴 ∈ 𝐵 ∧ 𝐴 ∉ 𝐶) → 𝐵 ≠ 𝐶) | ||
Theorem | elnelne2 3056 | Two classes are different if they don't belong to the same class. (Contributed by AV, 28-Jan-2020.) |
⊢ ((𝐴 ∈ 𝐶 ∧ 𝐵 ∉ 𝐶) → 𝐴 ≠ 𝐵) | ||
Theorem | pm2.24nel 3057 | A contradiction concerning membership implies anything. (Contributed by Alexander van der Vekens, 25-Jan-2018.) |
⊢ (𝐴 ∈ 𝐵 → (𝐴 ∉ 𝐵 → 𝜑)) | ||
Theorem | pm2.61danel 3058 | Deduction eliminating an elementhood in an antecedent. (Contributed by AV, 5-Dec-2021.) |
⊢ ((𝜑 ∧ 𝐴 ∈ 𝐵) → 𝜓) & ⊢ ((𝜑 ∧ 𝐴 ∉ 𝐵) → 𝜓) ⇒ ⊢ (𝜑 → 𝜓) | ||
Syntax | wral 3059 | Extend wff notation to include restricted universal quantification. |
wff ∀𝑥 ∈ 𝐴 𝜑 | ||
Definition | df-ral 3060 |
Define restricted universal quantification. Special case of Definition
4.15(3) of [TakeutiZaring] p. 22.
Note: This notation is most often used to express that 𝜑 holds for all elements of a given class 𝐴. For this reading Ⅎ𝑥𝐴 is required, though, for example, asserted when 𝑥 and 𝐴 are disjoint. Should instead 𝐴 depend on 𝑥, you rather focus on those 𝑥 that happen to be contained in the corresponding 𝐴(𝑥). This hardly used interpretation could still occur naturally. For some examples, look at ralndv1 46111 or ralndv2 46112, courtesy of AV. So be careful to either keep 𝐴 independent of 𝑥, or adjust your comments to include such exotic cases. (Contributed by NM, 19-Aug-1993.) |
⊢ (∀𝑥 ∈ 𝐴 𝜑 ↔ ∀𝑥(𝑥 ∈ 𝐴 → 𝜑)) | ||
Theorem | rgen 3061 | Generalization rule for restricted quantification. (Contributed by NM, 19-Nov-1994.) |
⊢ (𝑥 ∈ 𝐴 → 𝜑) ⇒ ⊢ ∀𝑥 ∈ 𝐴 𝜑 | ||
Theorem | ralel 3062 | All elements of a class are elements of the class. (Contributed by AV, 30-Oct-2020.) |
⊢ ∀𝑥 ∈ 𝐴 𝑥 ∈ 𝐴 | ||
Theorem | rgenw 3063 | Generalization rule for restricted quantification. (Contributed by NM, 18-Jun-2014.) |
⊢ 𝜑 ⇒ ⊢ ∀𝑥 ∈ 𝐴 𝜑 | ||
Theorem | rgen2w 3064 | Generalization rule for restricted quantification. Note that 𝑥 and 𝑦 needn't be distinct. (Contributed by NM, 18-Jun-2014.) |
⊢ 𝜑 ⇒ ⊢ ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐵 𝜑 | ||
Theorem | mprg 3065 | Modus ponens combined with restricted generalization. (Contributed by NM, 10-Aug-2004.) |
⊢ (∀𝑥 ∈ 𝐴 𝜑 → 𝜓) & ⊢ (𝑥 ∈ 𝐴 → 𝜑) ⇒ ⊢ 𝜓 | ||
Theorem | mprgbir 3066 | Modus ponens on biconditional combined with restricted generalization. (Contributed by NM, 21-Mar-2004.) |
⊢ (𝜑 ↔ ∀𝑥 ∈ 𝐴 𝜓) & ⊢ (𝑥 ∈ 𝐴 → 𝜓) ⇒ ⊢ 𝜑 | ||
Theorem | raln 3067 | Restricted universally quantified negation expressed as a universally quantified negation. (Contributed by BJ, 16-Jul-2021.) |
⊢ (∀𝑥 ∈ 𝐴 ¬ 𝜑 ↔ ∀𝑥 ¬ (𝑥 ∈ 𝐴 ∧ 𝜑)) | ||
Syntax | wrex 3068 | Extend wff notation to include restricted existential quantification. |
wff ∃𝑥 ∈ 𝐴 𝜑 | ||
Definition | df-rex 3069 |
Define restricted existential quantification. Special case of Definition
4.15(4) of [TakeutiZaring] p. 22.
Note: This notation is most often used to express that 𝜑 holds for at least one element of a given class 𝐴. For this reading Ⅎ𝑥𝐴 is required, though, for example, asserted when 𝑥 and 𝐴 are disjoint. Should instead 𝐴 depend on 𝑥, you rather assert at least one 𝑥 fulfilling 𝜑 happens to be contained in the corresponding 𝐴(𝑥). This interpretation is rarely needed (see also df-ral 3060). (Contributed by NM, 30-Aug-1993.) |
⊢ (∃𝑥 ∈ 𝐴 𝜑 ↔ ∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑)) | ||
Theorem | ralnex 3070 | Relationship between restricted universal and existential quantifiers. (Contributed by NM, 21-Jan-1997.) (Proof shortened by BJ, 16-Jul-2021.) |
⊢ (∀𝑥 ∈ 𝐴 ¬ 𝜑 ↔ ¬ ∃𝑥 ∈ 𝐴 𝜑) | ||
Theorem | dfrex2 3071 | Relationship between restricted universal and existential quantifiers. (Contributed by NM, 21-Jan-1997.) (Proof shortened by Wolf Lammen, 26-Nov-2019.) |
⊢ (∃𝑥 ∈ 𝐴 𝜑 ↔ ¬ ∀𝑥 ∈ 𝐴 ¬ 𝜑) | ||
Theorem | nrex 3072 | Inference adding restricted existential quantifier to negated wff. (Contributed by NM, 16-Oct-2003.) |
⊢ (𝑥 ∈ 𝐴 → ¬ 𝜓) ⇒ ⊢ ¬ ∃𝑥 ∈ 𝐴 𝜓 | ||
Theorem | alral 3073 | Universal quantification implies restricted quantification. (Contributed by NM, 20-Oct-2006.) |
⊢ (∀𝑥𝜑 → ∀𝑥 ∈ 𝐴 𝜑) | ||
Theorem | rexex 3074 | Restricted existence implies existence. (Contributed by NM, 11-Nov-1995.) |
⊢ (∃𝑥 ∈ 𝐴 𝜑 → ∃𝑥𝜑) | ||
Theorem | rextru 3075 | Two ways of expressing that a class has at least one element. (Contributed by Zhi Wang, 23-Sep-2024.) |
⊢ (∃𝑥 𝑥 ∈ 𝐴 ↔ ∃𝑥 ∈ 𝐴 ⊤) | ||
Theorem | ralimi2 3076 | Inference quantifying both antecedent and consequent. (Contributed by NM, 22-Feb-2004.) |
⊢ ((𝑥 ∈ 𝐴 → 𝜑) → (𝑥 ∈ 𝐵 → 𝜓)) ⇒ ⊢ (∀𝑥 ∈ 𝐴 𝜑 → ∀𝑥 ∈ 𝐵 𝜓) | ||
Theorem | reximi2 3077 | Inference quantifying both antecedent and consequent, based on Theorem 19.22 of [Margaris] p. 90. (Contributed by NM, 8-Nov-2004.) |
⊢ ((𝑥 ∈ 𝐴 ∧ 𝜑) → (𝑥 ∈ 𝐵 ∧ 𝜓)) ⇒ ⊢ (∃𝑥 ∈ 𝐴 𝜑 → ∃𝑥 ∈ 𝐵 𝜓) | ||
Theorem | ralimia 3078 | Inference quantifying both antecedent and consequent. (Contributed by NM, 19-Jul-1996.) |
⊢ (𝑥 ∈ 𝐴 → (𝜑 → 𝜓)) ⇒ ⊢ (∀𝑥 ∈ 𝐴 𝜑 → ∀𝑥 ∈ 𝐴 𝜓) | ||
Theorem | reximia 3079 | Inference quantifying both antecedent and consequent. (Contributed by NM, 10-Feb-1997.) (Proof shortened by Wolf Lammen, 31-Oct-2024.) |
⊢ (𝑥 ∈ 𝐴 → (𝜑 → 𝜓)) ⇒ ⊢ (∃𝑥 ∈ 𝐴 𝜑 → ∃𝑥 ∈ 𝐴 𝜓) | ||
Theorem | ralimiaa 3080 | Inference quantifying both antecedent and consequent. (Contributed by NM, 4-Aug-2007.) |
⊢ ((𝑥 ∈ 𝐴 ∧ 𝜑) → 𝜓) ⇒ ⊢ (∀𝑥 ∈ 𝐴 𝜑 → ∀𝑥 ∈ 𝐴 𝜓) | ||
Theorem | ralimi 3081 | Inference quantifying both antecedent and consequent, with strong hypothesis. (Contributed by NM, 4-Mar-1997.) |
⊢ (𝜑 → 𝜓) ⇒ ⊢ (∀𝑥 ∈ 𝐴 𝜑 → ∀𝑥 ∈ 𝐴 𝜓) | ||
Theorem | reximi 3082 | Inference quantifying both antecedent and consequent. (Contributed by NM, 18-Oct-1996.) |
⊢ (𝜑 → 𝜓) ⇒ ⊢ (∃𝑥 ∈ 𝐴 𝜑 → ∃𝑥 ∈ 𝐴 𝜓) | ||
Theorem | ral2imi 3083 | Inference quantifying antecedent, nested antecedent, and consequent, with a strong hypothesis. (Contributed by NM, 19-Dec-2006.) Allow shortening of ralim 3084. (Revised by Wolf Lammen, 1-Dec-2019.) |
⊢ (𝜑 → (𝜓 → 𝜒)) ⇒ ⊢ (∀𝑥 ∈ 𝐴 𝜑 → (∀𝑥 ∈ 𝐴 𝜓 → ∀𝑥 ∈ 𝐴 𝜒)) | ||
Theorem | ralim 3084 | Distribution of restricted quantification over implication. (Contributed by NM, 9-Feb-1997.) (Proof shortened by Wolf Lammen, 1-Dec-2019.) |
⊢ (∀𝑥 ∈ 𝐴 (𝜑 → 𝜓) → (∀𝑥 ∈ 𝐴 𝜑 → ∀𝑥 ∈ 𝐴 𝜓)) | ||
Theorem | rexim 3085 | Theorem 19.22 of [Margaris] p. 90. (Restricted quantifier version.) (Contributed by NM, 22-Nov-1994.) (Proof shortened by Andrew Salmon, 30-May-2011.) |
⊢ (∀𝑥 ∈ 𝐴 (𝜑 → 𝜓) → (∃𝑥 ∈ 𝐴 𝜑 → ∃𝑥 ∈ 𝐴 𝜓)) | ||
Theorem | reximiaOLD 3086 | Obsolete version of reximia 3079 as of 31-Oct-2024. (Contributed by NM, 10-Feb-1997.) (Proof modification is discouraged.) (New usage is discouraged.) |
⊢ (𝑥 ∈ 𝐴 → (𝜑 → 𝜓)) ⇒ ⊢ (∃𝑥 ∈ 𝐴 𝜑 → ∃𝑥 ∈ 𝐴 𝜓) | ||
Theorem | ralbii2 3087 | Inference adding different restricted universal quantifiers to each side of an equivalence. (Contributed by NM, 15-Aug-2005.) |
⊢ ((𝑥 ∈ 𝐴 → 𝜑) ↔ (𝑥 ∈ 𝐵 → 𝜓)) ⇒ ⊢ (∀𝑥 ∈ 𝐴 𝜑 ↔ ∀𝑥 ∈ 𝐵 𝜓) | ||
Theorem | rexbii2 3088 | Inference adding different restricted existential quantifiers to each side of an equivalence. (Contributed by NM, 4-Feb-2004.) |
⊢ ((𝑥 ∈ 𝐴 ∧ 𝜑) ↔ (𝑥 ∈ 𝐵 ∧ 𝜓)) ⇒ ⊢ (∃𝑥 ∈ 𝐴 𝜑 ↔ ∃𝑥 ∈ 𝐵 𝜓) | ||
Theorem | ralbiia 3089 | Inference adding restricted universal quantifier to both sides of an equivalence. (Contributed by NM, 26-Nov-2000.) |
⊢ (𝑥 ∈ 𝐴 → (𝜑 ↔ 𝜓)) ⇒ ⊢ (∀𝑥 ∈ 𝐴 𝜑 ↔ ∀𝑥 ∈ 𝐴 𝜓) | ||
Theorem | rexbiia 3090 | Inference adding restricted existential quantifier to both sides of an equivalence. (Contributed by NM, 26-Oct-1999.) |
⊢ (𝑥 ∈ 𝐴 → (𝜑 ↔ 𝜓)) ⇒ ⊢ (∃𝑥 ∈ 𝐴 𝜑 ↔ ∃𝑥 ∈ 𝐴 𝜓) | ||
Theorem | ralbii 3091 | Inference adding restricted universal quantifier to both sides of an equivalence. (Contributed by NM, 23-Nov-1994.) (Revised by Mario Carneiro, 17-Oct-2016.) (Proof shortened by Wolf Lammen, 4-Dec-2019.) |
⊢ (𝜑 ↔ 𝜓) ⇒ ⊢ (∀𝑥 ∈ 𝐴 𝜑 ↔ ∀𝑥 ∈ 𝐴 𝜓) | ||
Theorem | rexbii 3092 | Inference adding restricted existential quantifier to both sides of an equivalence. (Contributed by NM, 23-Nov-1994.) (Revised by Mario Carneiro, 17-Oct-2016.) (Proof shortened by Wolf Lammen, 6-Dec-2019.) |
⊢ (𝜑 ↔ 𝜓) ⇒ ⊢ (∃𝑥 ∈ 𝐴 𝜑 ↔ ∃𝑥 ∈ 𝐴 𝜓) | ||
Theorem | ralanid 3093 | Cancellation law for restricted universal quantification. (Contributed by Peter Mazsa, 30-Dec-2018.) (Proof shortened by Wolf Lammen, 29-Jun-2023.) |
⊢ (∀𝑥 ∈ 𝐴 (𝑥 ∈ 𝐴 ∧ 𝜑) ↔ ∀𝑥 ∈ 𝐴 𝜑) | ||
Theorem | rexanid 3094 | Cancellation law for restricted existential quantification. (Contributed by Peter Mazsa, 24-May-2018.) (Proof shortened by Wolf Lammen, 8-Jul-2023.) |
⊢ (∃𝑥 ∈ 𝐴 (𝑥 ∈ 𝐴 ∧ 𝜑) ↔ ∃𝑥 ∈ 𝐴 𝜑) | ||
Theorem | ralcom3 3095 | A commutation law for restricted universal quantifiers that swaps the domains of the restriction. (Contributed by NM, 22-Feb-2004.) (Proof shortened by Wolf Lammen, 22-Dec-2024.) |
⊢ (∀𝑥 ∈ 𝐴 (𝑥 ∈ 𝐵 → 𝜑) ↔ ∀𝑥 ∈ 𝐵 (𝑥 ∈ 𝐴 → 𝜑)) | ||
Theorem | ralcom3OLD 3096 | Obsolete version of ralcom3 3095 as of 22-Dec-2024. (Contributed by NM, 22-Feb-2004.) (Proof modification is discouraged.) (New usage is discouraged.) |
⊢ (∀𝑥 ∈ 𝐴 (𝑥 ∈ 𝐵 → 𝜑) ↔ ∀𝑥 ∈ 𝐵 (𝑥 ∈ 𝐴 → 𝜑)) | ||
Theorem | dfral2 3097 | Relationship between restricted universal and existential quantifiers. (Contributed by NM, 21-Jan-1997.) Allow shortening of rexnal 3098. (Revised by Wolf Lammen, 9-Dec-2019.) |
⊢ (∀𝑥 ∈ 𝐴 𝜑 ↔ ¬ ∃𝑥 ∈ 𝐴 ¬ 𝜑) | ||
Theorem | rexnal 3098 | Relationship between restricted universal and existential quantifiers. (Contributed by NM, 21-Jan-1997.) (Proof shortened by Wolf Lammen, 9-Dec-2019.) |
⊢ (∃𝑥 ∈ 𝐴 ¬ 𝜑 ↔ ¬ ∀𝑥 ∈ 𝐴 𝜑) | ||
Theorem | ralinexa 3099 | A transformation of restricted quantifiers and logical connectives. (Contributed by NM, 4-Sep-2005.) |
⊢ (∀𝑥 ∈ 𝐴 (𝜑 → ¬ 𝜓) ↔ ¬ ∃𝑥 ∈ 𝐴 (𝜑 ∧ 𝜓)) | ||
Theorem | rexanali 3100 | A transformation of restricted quantifiers and logical connectives. (Contributed by NM, 4-Sep-2005.) (Proof shortened by Wolf Lammen, 27-Dec-2019.) |
⊢ (∃𝑥 ∈ 𝐴 (𝜑 ∧ ¬ 𝜓) ↔ ¬ ∀𝑥 ∈ 𝐴 (𝜑 → 𝜓)) |
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