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Description: Limit of the reciprocal of a converging sequence. (Contributed by Glauco Siliprandi, 29-Jun-2017)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | climrec.1 | ⊢ 𝑍 = ( ℤ≥ ‘ 𝑀 ) | |
| climrec.2 | ⊢ ( 𝜑 → 𝑀 ∈ ℤ ) | ||
| climrec.3 | ⊢ ( 𝜑 → 𝐺 ⇝ 𝐴 ) | ||
| climrec.4 | ⊢ ( 𝜑 → 𝐴 ≠ 0 ) | ||
| climrec.5 | ⊢ ( ( 𝜑 ∧ 𝑘 ∈ 𝑍 ) → ( 𝐺 ‘ 𝑘 ) ∈ ( ℂ ∖ { 0 } ) ) | ||
| climrec.6 | ⊢ ( ( 𝜑 ∧ 𝑘 ∈ 𝑍 ) → ( 𝐻 ‘ 𝑘 ) = ( 1 / ( 𝐺 ‘ 𝑘 ) ) ) | ||
| climrec.7 | ⊢ ( 𝜑 → 𝐻 ∈ 𝑊 ) | ||
| Assertion | climrec | ⊢ ( 𝜑 → 𝐻 ⇝ ( 1 / 𝐴 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | climrec.1 | ⊢ 𝑍 = ( ℤ≥ ‘ 𝑀 ) | |
| 2 | climrec.2 | ⊢ ( 𝜑 → 𝑀 ∈ ℤ ) | |
| 3 | climrec.3 | ⊢ ( 𝜑 → 𝐺 ⇝ 𝐴 ) | |
| 4 | climrec.4 | ⊢ ( 𝜑 → 𝐴 ≠ 0 ) | |
| 5 | climrec.5 | ⊢ ( ( 𝜑 ∧ 𝑘 ∈ 𝑍 ) → ( 𝐺 ‘ 𝑘 ) ∈ ( ℂ ∖ { 0 } ) ) | |
| 6 | climrec.6 | ⊢ ( ( 𝜑 ∧ 𝑘 ∈ 𝑍 ) → ( 𝐻 ‘ 𝑘 ) = ( 1 / ( 𝐺 ‘ 𝑘 ) ) ) | |
| 7 | climrec.7 | ⊢ ( 𝜑 → 𝐻 ∈ 𝑊 ) | |
| 8 | climcl | ⊢ ( 𝐺 ⇝ 𝐴 → 𝐴 ∈ ℂ ) | |
| 9 | 3 8 | syl | ⊢ ( 𝜑 → 𝐴 ∈ ℂ ) |
| 10 | 4 | neneqd | ⊢ ( 𝜑 → ¬ 𝐴 = 0 ) |
| 11 | c0ex | ⊢ 0 ∈ V | |
| 12 | 11 | elsn2 | ⊢ ( 𝐴 ∈ { 0 } ↔ 𝐴 = 0 ) |
| 13 | 10 12 | sylnibr | ⊢ ( 𝜑 → ¬ 𝐴 ∈ { 0 } ) |
| 14 | 9 13 | eldifd | ⊢ ( 𝜑 → 𝐴 ∈ ( ℂ ∖ { 0 } ) ) |
| 15 | eqidd | ⊢ ( ( 𝜑 ∧ 𝑧 ∈ ( ℂ ∖ { 0 } ) ) → ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) = ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) ) | |
| 16 | simpr | ⊢ ( ( ( 𝜑 ∧ 𝑧 ∈ ( ℂ ∖ { 0 } ) ) ∧ 𝑤 = 𝑧 ) → 𝑤 = 𝑧 ) | |
| 17 | 16 | oveq2d | ⊢ ( ( ( 𝜑 ∧ 𝑧 ∈ ( ℂ ∖ { 0 } ) ) ∧ 𝑤 = 𝑧 ) → ( 1 / 𝑤 ) = ( 1 / 𝑧 ) ) |
| 18 | simpr | ⊢ ( ( 𝜑 ∧ 𝑧 ∈ ( ℂ ∖ { 0 } ) ) → 𝑧 ∈ ( ℂ ∖ { 0 } ) ) | |
| 19 | 18 | eldifad | ⊢ ( ( 𝜑 ∧ 𝑧 ∈ ( ℂ ∖ { 0 } ) ) → 𝑧 ∈ ℂ ) |
| 20 | eldifsni | ⊢ ( 𝑧 ∈ ( ℂ ∖ { 0 } ) → 𝑧 ≠ 0 ) | |
| 21 | 20 | adantl | ⊢ ( ( 𝜑 ∧ 𝑧 ∈ ( ℂ ∖ { 0 } ) ) → 𝑧 ≠ 0 ) |
| 22 | 19 21 | reccld | ⊢ ( ( 𝜑 ∧ 𝑧 ∈ ( ℂ ∖ { 0 } ) ) → ( 1 / 𝑧 ) ∈ ℂ ) |
| 23 | 15 17 18 22 | fvmptd | ⊢ ( ( 𝜑 ∧ 𝑧 ∈ ( ℂ ∖ { 0 } ) ) → ( ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) ‘ 𝑧 ) = ( 1 / 𝑧 ) ) |
| 24 | 23 22 | eqeltrd | ⊢ ( ( 𝜑 ∧ 𝑧 ∈ ( ℂ ∖ { 0 } ) ) → ( ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) ‘ 𝑧 ) ∈ ℂ ) |
| 25 | eqid | ⊢ ( if ( 1 ≤ ( ( abs ‘ 𝐴 ) · 𝑥 ) , 1 , ( ( abs ‘ 𝐴 ) · 𝑥 ) ) · ( ( abs ‘ 𝐴 ) / 2 ) ) = ( if ( 1 ≤ ( ( abs ‘ 𝐴 ) · 𝑥 ) , 1 , ( ( abs ‘ 𝐴 ) · 𝑥 ) ) · ( ( abs ‘ 𝐴 ) / 2 ) ) | |
| 26 | 25 | reccn2 | ⊢ ( ( 𝐴 ∈ ( ℂ ∖ { 0 } ) ∧ 𝑥 ∈ ℝ+ ) → ∃ 𝑦 ∈ ℝ+ ∀ 𝑧 ∈ ( ℂ ∖ { 0 } ) ( ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 → ( abs ‘ ( ( 1 / 𝑧 ) − ( 1 / 𝐴 ) ) ) < 𝑥 ) ) |
| 27 | 14 26 | sylan | ⊢ ( ( 𝜑 ∧ 𝑥 ∈ ℝ+ ) → ∃ 𝑦 ∈ ℝ+ ∀ 𝑧 ∈ ( ℂ ∖ { 0 } ) ( ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 → ( abs ‘ ( ( 1 / 𝑧 ) − ( 1 / 𝐴 ) ) ) < 𝑥 ) ) |
| 28 | eqidd | ⊢ ( 𝑧 ∈ ( ℂ ∖ { 0 } ) → ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) = ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) ) | |
| 29 | simpr | ⊢ ( ( 𝑧 ∈ ( ℂ ∖ { 0 } ) ∧ 𝑤 = 𝑧 ) → 𝑤 = 𝑧 ) | |
| 30 | 29 | oveq2d | ⊢ ( ( 𝑧 ∈ ( ℂ ∖ { 0 } ) ∧ 𝑤 = 𝑧 ) → ( 1 / 𝑤 ) = ( 1 / 𝑧 ) ) |
| 31 | id | ⊢ ( 𝑧 ∈ ( ℂ ∖ { 0 } ) → 𝑧 ∈ ( ℂ ∖ { 0 } ) ) | |
| 32 | eldifi | ⊢ ( 𝑧 ∈ ( ℂ ∖ { 0 } ) → 𝑧 ∈ ℂ ) | |
| 33 | 32 20 | reccld | ⊢ ( 𝑧 ∈ ( ℂ ∖ { 0 } ) → ( 1 / 𝑧 ) ∈ ℂ ) |
| 34 | 28 30 31 33 | fvmptd | ⊢ ( 𝑧 ∈ ( ℂ ∖ { 0 } ) → ( ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) ‘ 𝑧 ) = ( 1 / 𝑧 ) ) |
| 35 | 34 | ad2antlr | ⊢ ( ( ( ( ( 𝜑 ∧ 𝑥 ∈ ℝ+ ) ∧ ( 𝑧 ∈ ( ℂ ∖ { 0 } ) → ( ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 → ( abs ‘ ( ( 1 / 𝑧 ) − ( 1 / 𝐴 ) ) ) < 𝑥 ) ) ) ∧ 𝑧 ∈ ( ℂ ∖ { 0 } ) ) ∧ ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 ) → ( ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) ‘ 𝑧 ) = ( 1 / 𝑧 ) ) |
| 36 | eqidd | ⊢ ( 𝜑 → ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) = ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) ) | |
| 37 | simpr | ⊢ ( ( 𝜑 ∧ 𝑤 = 𝐴 ) → 𝑤 = 𝐴 ) | |
| 38 | 37 | oveq2d | ⊢ ( ( 𝜑 ∧ 𝑤 = 𝐴 ) → ( 1 / 𝑤 ) = ( 1 / 𝐴 ) ) |
| 39 | 9 4 | reccld | ⊢ ( 𝜑 → ( 1 / 𝐴 ) ∈ ℂ ) |
| 40 | 36 38 14 39 | fvmptd | ⊢ ( 𝜑 → ( ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) ‘ 𝐴 ) = ( 1 / 𝐴 ) ) |
| 41 | 40 | ad4antr | ⊢ ( ( ( ( ( 𝜑 ∧ 𝑥 ∈ ℝ+ ) ∧ ( 𝑧 ∈ ( ℂ ∖ { 0 } ) → ( ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 → ( abs ‘ ( ( 1 / 𝑧 ) − ( 1 / 𝐴 ) ) ) < 𝑥 ) ) ) ∧ 𝑧 ∈ ( ℂ ∖ { 0 } ) ) ∧ ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 ) → ( ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) ‘ 𝐴 ) = ( 1 / 𝐴 ) ) |
| 42 | 35 41 | oveq12d | ⊢ ( ( ( ( ( 𝜑 ∧ 𝑥 ∈ ℝ+ ) ∧ ( 𝑧 ∈ ( ℂ ∖ { 0 } ) → ( ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 → ( abs ‘ ( ( 1 / 𝑧 ) − ( 1 / 𝐴 ) ) ) < 𝑥 ) ) ) ∧ 𝑧 ∈ ( ℂ ∖ { 0 } ) ) ∧ ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 ) → ( ( ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) ‘ 𝑧 ) − ( ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) ‘ 𝐴 ) ) = ( ( 1 / 𝑧 ) − ( 1 / 𝐴 ) ) ) |
| 43 | 42 | fveq2d | ⊢ ( ( ( ( ( 𝜑 ∧ 𝑥 ∈ ℝ+ ) ∧ ( 𝑧 ∈ ( ℂ ∖ { 0 } ) → ( ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 → ( abs ‘ ( ( 1 / 𝑧 ) − ( 1 / 𝐴 ) ) ) < 𝑥 ) ) ) ∧ 𝑧 ∈ ( ℂ ∖ { 0 } ) ) ∧ ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 ) → ( abs ‘ ( ( ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) ‘ 𝑧 ) − ( ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) ‘ 𝐴 ) ) ) = ( abs ‘ ( ( 1 / 𝑧 ) − ( 1 / 𝐴 ) ) ) ) |
| 44 | 31 | ad2antlr | ⊢ ( ( ( ( ( 𝜑 ∧ 𝑥 ∈ ℝ+ ) ∧ ( 𝑧 ∈ ( ℂ ∖ { 0 } ) → ( ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 → ( abs ‘ ( ( 1 / 𝑧 ) − ( 1 / 𝐴 ) ) ) < 𝑥 ) ) ) ∧ 𝑧 ∈ ( ℂ ∖ { 0 } ) ) ∧ ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 ) → 𝑧 ∈ ( ℂ ∖ { 0 } ) ) |
| 45 | simpr | ⊢ ( ( ( ( ( 𝜑 ∧ 𝑥 ∈ ℝ+ ) ∧ ( 𝑧 ∈ ( ℂ ∖ { 0 } ) → ( ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 → ( abs ‘ ( ( 1 / 𝑧 ) − ( 1 / 𝐴 ) ) ) < 𝑥 ) ) ) ∧ 𝑧 ∈ ( ℂ ∖ { 0 } ) ) ∧ ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 ) → ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 ) | |
| 46 | simpllr | ⊢ ( ( ( ( ( 𝜑 ∧ 𝑥 ∈ ℝ+ ) ∧ ( 𝑧 ∈ ( ℂ ∖ { 0 } ) → ( ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 → ( abs ‘ ( ( 1 / 𝑧 ) − ( 1 / 𝐴 ) ) ) < 𝑥 ) ) ) ∧ 𝑧 ∈ ( ℂ ∖ { 0 } ) ) ∧ ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 ) → ( 𝑧 ∈ ( ℂ ∖ { 0 } ) → ( ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 → ( abs ‘ ( ( 1 / 𝑧 ) − ( 1 / 𝐴 ) ) ) < 𝑥 ) ) ) | |
| 47 | 44 45 46 | mp2d | ⊢ ( ( ( ( ( 𝜑 ∧ 𝑥 ∈ ℝ+ ) ∧ ( 𝑧 ∈ ( ℂ ∖ { 0 } ) → ( ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 → ( abs ‘ ( ( 1 / 𝑧 ) − ( 1 / 𝐴 ) ) ) < 𝑥 ) ) ) ∧ 𝑧 ∈ ( ℂ ∖ { 0 } ) ) ∧ ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 ) → ( abs ‘ ( ( 1 / 𝑧 ) − ( 1 / 𝐴 ) ) ) < 𝑥 ) |
| 48 | 43 47 | eqbrtrd | ⊢ ( ( ( ( ( 𝜑 ∧ 𝑥 ∈ ℝ+ ) ∧ ( 𝑧 ∈ ( ℂ ∖ { 0 } ) → ( ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 → ( abs ‘ ( ( 1 / 𝑧 ) − ( 1 / 𝐴 ) ) ) < 𝑥 ) ) ) ∧ 𝑧 ∈ ( ℂ ∖ { 0 } ) ) ∧ ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 ) → ( abs ‘ ( ( ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) ‘ 𝑧 ) − ( ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) ‘ 𝐴 ) ) ) < 𝑥 ) |
| 49 | 48 | exp41 | ⊢ ( ( 𝜑 ∧ 𝑥 ∈ ℝ+ ) → ( ( 𝑧 ∈ ( ℂ ∖ { 0 } ) → ( ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 → ( abs ‘ ( ( 1 / 𝑧 ) − ( 1 / 𝐴 ) ) ) < 𝑥 ) ) → ( 𝑧 ∈ ( ℂ ∖ { 0 } ) → ( ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 → ( abs ‘ ( ( ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) ‘ 𝑧 ) − ( ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) ‘ 𝐴 ) ) ) < 𝑥 ) ) ) ) |
| 50 | 49 | ralimdv2 | ⊢ ( ( 𝜑 ∧ 𝑥 ∈ ℝ+ ) → ( ∀ 𝑧 ∈ ( ℂ ∖ { 0 } ) ( ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 → ( abs ‘ ( ( 1 / 𝑧 ) − ( 1 / 𝐴 ) ) ) < 𝑥 ) → ∀ 𝑧 ∈ ( ℂ ∖ { 0 } ) ( ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 → ( abs ‘ ( ( ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) ‘ 𝑧 ) − ( ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) ‘ 𝐴 ) ) ) < 𝑥 ) ) ) |
| 51 | 50 | reximdv | ⊢ ( ( 𝜑 ∧ 𝑥 ∈ ℝ+ ) → ( ∃ 𝑦 ∈ ℝ+ ∀ 𝑧 ∈ ( ℂ ∖ { 0 } ) ( ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 → ( abs ‘ ( ( 1 / 𝑧 ) − ( 1 / 𝐴 ) ) ) < 𝑥 ) → ∃ 𝑦 ∈ ℝ+ ∀ 𝑧 ∈ ( ℂ ∖ { 0 } ) ( ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 → ( abs ‘ ( ( ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) ‘ 𝑧 ) − ( ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) ‘ 𝐴 ) ) ) < 𝑥 ) ) ) |
| 52 | 27 51 | mpd | ⊢ ( ( 𝜑 ∧ 𝑥 ∈ ℝ+ ) → ∃ 𝑦 ∈ ℝ+ ∀ 𝑧 ∈ ( ℂ ∖ { 0 } ) ( ( abs ‘ ( 𝑧 − 𝐴 ) ) < 𝑦 → ( abs ‘ ( ( ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) ‘ 𝑧 ) − ( ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) ‘ 𝐴 ) ) ) < 𝑥 ) ) |
| 53 | eqidd | ⊢ ( ( 𝜑 ∧ 𝑘 ∈ 𝑍 ) → ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) = ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) ) | |
| 54 | oveq2 | ⊢ ( 𝑤 = ( 𝐺 ‘ 𝑘 ) → ( 1 / 𝑤 ) = ( 1 / ( 𝐺 ‘ 𝑘 ) ) ) | |
| 55 | 54 | adantl | ⊢ ( ( ( 𝜑 ∧ 𝑘 ∈ 𝑍 ) ∧ 𝑤 = ( 𝐺 ‘ 𝑘 ) ) → ( 1 / 𝑤 ) = ( 1 / ( 𝐺 ‘ 𝑘 ) ) ) |
| 56 | 5 | eldifad | ⊢ ( ( 𝜑 ∧ 𝑘 ∈ 𝑍 ) → ( 𝐺 ‘ 𝑘 ) ∈ ℂ ) |
| 57 | eldifsni | ⊢ ( ( 𝐺 ‘ 𝑘 ) ∈ ( ℂ ∖ { 0 } ) → ( 𝐺 ‘ 𝑘 ) ≠ 0 ) | |
| 58 | 5 57 | syl | ⊢ ( ( 𝜑 ∧ 𝑘 ∈ 𝑍 ) → ( 𝐺 ‘ 𝑘 ) ≠ 0 ) |
| 59 | 56 58 | reccld | ⊢ ( ( 𝜑 ∧ 𝑘 ∈ 𝑍 ) → ( 1 / ( 𝐺 ‘ 𝑘 ) ) ∈ ℂ ) |
| 60 | 53 55 5 59 | fvmptd | ⊢ ( ( 𝜑 ∧ 𝑘 ∈ 𝑍 ) → ( ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) ‘ ( 𝐺 ‘ 𝑘 ) ) = ( 1 / ( 𝐺 ‘ 𝑘 ) ) ) |
| 61 | 6 60 | eqtr4d | ⊢ ( ( 𝜑 ∧ 𝑘 ∈ 𝑍 ) → ( 𝐻 ‘ 𝑘 ) = ( ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) ‘ ( 𝐺 ‘ 𝑘 ) ) ) |
| 62 | 1 2 14 24 3 7 52 5 61 | climcn1 | ⊢ ( 𝜑 → 𝐻 ⇝ ( ( 𝑤 ∈ ( ℂ ∖ { 0 } ) ↦ ( 1 / 𝑤 ) ) ‘ 𝐴 ) ) |
| 63 | 62 40 | breqtrd | ⊢ ( 𝜑 → 𝐻 ⇝ ( 1 / 𝐴 ) ) |