P. 429 of Theorem List - Metamath Proof Explorer

Theorem List for Metamath Proof Explorer - 42801-42900   *Has distinct variable group(s)

Type	Label	Description
Statement
Theorem	explt1d 42801	A nonnegative real number less than one raised to a positive integer is less than one. (Contributed by SN, 3-Jul-2025.)
⊢ (𝜑 → 𝐴 ∈ ℝ)    &   ⊢ (𝜑 → 𝑁 ∈ ℕ)    &   ⊢ (𝜑 → 0 ≤ 𝐴)    &   ⊢ (𝜑 → 𝐴 < 1)    ⇒   ⊢ (𝜑 → (𝐴↑𝑁) < 1)
Theorem	expeq1d 42802	A nonnegative real number is one if and only if it is one when raised to a positive integer. (Contributed by SN, 3-Jul-2025.)
⊢ (𝜑 → 𝐴 ∈ ℝ)    &   ⊢ (𝜑 → 𝑁 ∈ ℕ)    &   ⊢ (𝜑 → 0 ≤ 𝐴)    ⇒   ⊢ (𝜑 → ((𝐴↑𝑁) = 1 ↔ 𝐴 = 1))
Theorem	expeqidd 42803	A nonnegative real number is zero or one if and only if it is itself when raised to an integer greater than one. (Contributed by SN, 3-Jul-2025.)
⊢ (𝜑 → 𝐴 ∈ ℝ)    &   ⊢ (𝜑 → 𝑁 ∈ (ℤ≥‘2))    &   ⊢ (𝜑 → 0 ≤ 𝐴)    ⇒   ⊢ (𝜑 → ((𝐴↑𝑁) = 𝐴 ↔ (𝐴 = 0 ∨ 𝐴 = 1)))
Theorem	exp11d 42804	exp11nnd 14221 for nonzero integer exponents. (Contributed by SN, 14-Sep-2023.)
⊢ (𝜑 → 𝐴 ∈ ℝ+)    &   ⊢ (𝜑 → 𝐵 ∈ ℝ+)    &   ⊢ (𝜑 → 𝑁 ∈ ℤ)    &   ⊢ (𝜑 → 𝑁 ≠ 0)    &   ⊢ (𝜑 → (𝐴↑𝑁) = (𝐵↑𝑁))    ⇒   ⊢ (𝜑 → 𝐴 = 𝐵)
Theorem	0dvds0 42805	0 divides 0. (Contributed by SN, 15-Sep-2024.)
⊢ 0 ∥ 0
Theorem	absdvdsabsb 42806	Divisibility is invariant under taking the absolute value on both sides. (Contributed by SN, 15-Sep-2024.)
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝑀 ∥ 𝑁 ↔ (abs‘𝑀) ∥ (abs‘𝑁)))
Theorem	gcdnn0id 42807	The gcd of a nonnegative integer and itself is the integer. (Contributed by SN, 25-Aug-2024.)
⊢ (𝑁 ∈ ℕ0 → (𝑁 gcd 𝑁) = 𝑁)
Theorem	gcdle1d 42808	The greatest common divisor of a positive integer and another integer is less than or equal to the positive integer. (Contributed by SN, 25-Aug-2024.)
⊢ (𝜑 → 𝑀 ∈ ℕ)    &   ⊢ (𝜑 → 𝑁 ∈ ℤ)    ⇒   ⊢ (𝜑 → (𝑀 gcd 𝑁) ≤ 𝑀)
Theorem	gcdle2d 42809	The greatest common divisor of a positive integer and another integer is less than or equal to the positive integer. (Contributed by SN, 25-Aug-2024.)
⊢ (𝜑 → 𝑀 ∈ ℤ)    &   ⊢ (𝜑 → 𝑁 ∈ ℕ)    ⇒   ⊢ (𝜑 → (𝑀 gcd 𝑁) ≤ 𝑁)
Theorem	dvdsexpad 42810	Deduction associated with dvdsexpim 16522. (Contributed by SN, 21-Aug-2024.)
⊢ (𝜑 → 𝐴 ∈ ℤ)    &   ⊢ (𝜑 → 𝐵 ∈ ℤ)    &   ⊢ (𝜑 → 𝑁 ∈ ℕ0)    &   ⊢ (𝜑 → 𝐴 ∥ 𝐵)    ⇒   ⊢ (𝜑 → (𝐴↑𝑁) ∥ (𝐵↑𝑁))
Theorem	dvdsexpnn 42811	dvdssqlem 16533 generalized to positive integer exponents. (Contributed by SN, 20-Aug-2024.)
⊢ ((𝐴 ∈ ℕ ∧ 𝐵 ∈ ℕ ∧ 𝑁 ∈ ℕ) → (𝐴 ∥ 𝐵 ↔ (𝐴↑𝑁) ∥ (𝐵↑𝑁)))
Theorem	dvdsexpnn0 42812	dvdsexpnn 42811 generalized to include zero bases. (Contributed by SN, 15-Sep-2024.)
⊢ ((𝐴 ∈ ℕ0 ∧ 𝐵 ∈ ℕ0 ∧ 𝑁 ∈ ℕ) → (𝐴 ∥ 𝐵 ↔ (𝐴↑𝑁) ∥ (𝐵↑𝑁)))
Theorem	dvdsexpb 42813	dvdssq 16534 generalized to positive integer exponents. (Contributed by SN, 15-Sep-2024.)
⊢ ((𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝑁 ∈ ℕ) → (𝐴 ∥ 𝐵 ↔ (𝐴↑𝑁) ∥ (𝐵↑𝑁)))
Theorem	posqsqznn 42814	When a positive rational squared is an integer, the rational is a positive integer. zsqrtelqelz 16726 with all terms squared and positive. (Contributed by SN, 23-Aug-2024.)
⊢ (𝜑 → (𝐴↑2) ∈ ℤ)    &   ⊢ (𝜑 → 𝐴 ∈ ℚ)    &   ⊢ (𝜑 → 0 < 𝐴)    ⇒   ⊢ (𝜑 → 𝐴 ∈ ℕ)
Theorem	zdivgd 42815*	Two ways to express "𝑁 is an integer multiple of 𝑀". Originally a subproof of zdiv 12597. (Contributed by SN, 25-Apr-2025.)
⊢ (𝜑 → 𝑀 ∈ ℂ)    &   ⊢ (𝜑 → 𝑁 ∈ ℂ)    &   ⊢ (𝜑 → 𝑀 ≠ 0)    ⇒   ⊢ (𝜑 → (∃𝑘 ∈ ℤ (𝑀 · 𝑘) = 𝑁 ↔ (𝑁 / 𝑀) ∈ ℤ))
Theorem	efsubd 42816	Difference of exponents law for exponential function, deduction form. (Contributed by SN, 25-Apr-2025.)
⊢ (𝜑 → 𝐴 ∈ ℂ)    &   ⊢ (𝜑 → 𝐵 ∈ ℂ)    ⇒   ⊢ (𝜑 → (exp‘(𝐴 − 𝐵)) = ((exp‘𝐴) / (exp‘𝐵)))
Theorem	ef11d 42817*	General condition for the exponential function to be one-to-one. efper 26468 shows that exponentiation is periodic. (Contributed by SN, 25-Apr-2025.)
⊢ (𝜑 → 𝐴 ∈ ℂ)    &   ⊢ (𝜑 → 𝐵 ∈ ℂ)    ⇒   ⊢ (𝜑 → ((exp‘𝐴) = (exp‘𝐵) ↔ ∃𝑛 ∈ ℤ 𝐴 = (𝐵 + ((i · (2 · π)) · 𝑛))))
Theorem	logccne0d 42818	The logarithm isn't 0 if its argument isn't 0 or 1, deduction form. (Contributed by SN, 25-Apr-2025.)
⊢ (𝜑 → 𝐴 ∈ ℂ)    &   ⊢ (𝜑 → 𝐴 ≠ 0)    &   ⊢ (𝜑 → 𝐴 ≠ 1)    ⇒   ⊢ (𝜑 → (log‘𝐴) ≠ 0)
Theorem	cxp112d 42819*	General condition for complex exponentiation to be one-to-one with respect to the second argument. (Contributed by SN, 25-Apr-2025.)
⊢ (𝜑 → 𝐶 ∈ ℂ)    &   ⊢ (𝜑 → 𝐴 ∈ ℂ)    &   ⊢ (𝜑 → 𝐵 ∈ ℂ)    &   ⊢ (𝜑 → 𝐶 ≠ 0)    &   ⊢ (𝜑 → 𝐶 ≠ 1)    ⇒   ⊢ (𝜑 → ((𝐶↑𝑐𝐴) = (𝐶↑𝑐𝐵) ↔ ∃𝑛 ∈ ℤ 𝐴 = (𝐵 + (((i · (2 · π)) · 𝑛) / (log‘𝐶)))))
Theorem	cxp111d 42820*	General condition for complex exponentiation to be one-to-one with respect to the first argument. (Contributed by SN, 25-Apr-2025.)
⊢ (𝜑 → 𝐴 ∈ ℂ)    &   ⊢ (𝜑 → 𝐵 ∈ ℂ)    &   ⊢ (𝜑 → 𝐶 ∈ ℂ)    &   ⊢ (𝜑 → 𝐴 ≠ 0)    &   ⊢ (𝜑 → 𝐵 ≠ 0)    &   ⊢ (𝜑 → 𝐶 ≠ 0)    ⇒   ⊢ (𝜑 → ((𝐴↑𝑐𝐶) = (𝐵↑𝑐𝐶) ↔ ∃𝑛 ∈ ℤ (log‘𝐴) = ((log‘𝐵) + (((i · (2 · π)) · 𝑛) / 𝐶))))
Theorem	cxpi11d 42821*	i to the powers of 𝐴 and 𝐵 are equal iff 𝐴 and 𝐵 are a multiple of 4 apart. EDITORIAL: This theorem may be revised to a more convenient form. (Contributed by SN, 25-Apr-2025.)
⊢ (𝜑 → 𝐴 ∈ ℂ)    &   ⊢ (𝜑 → 𝐵 ∈ ℂ)    ⇒   ⊢ (𝜑 → ((i↑𝑐𝐴) = (i↑𝑐𝐵) ↔ ∃𝑛 ∈ ℤ 𝐴 = (𝐵 + (4 · 𝑛))))
Theorem	logne0d 42822	Deduction form of logne0 26568. See logccne0d 42818 for a more general version. (Contributed by SN, 25-Apr-2025.)
⊢ (𝜑 → 𝐴 ∈ ℝ+)    &   ⊢ (𝜑 → 𝐴 ≠ 1)    ⇒   ⊢ (𝜑 → (log‘𝐴) ≠ 0)
Theorem	rxp112d 42823	Real exponentiation is one-to-one with respect to the second argument. (TODO: Note that the base 𝐶 must be positive since -𝐶↑𝐴 is 𝐶↑𝐴 · e↑iπ𝐴, so in the negative case 𝐴 = 𝐵 + 2𝑘). (Contributed by SN, 25-Apr-2025.)
⊢ (𝜑 → 𝐶 ∈ ℝ+)    &   ⊢ (𝜑 → 𝐴 ∈ ℝ)    &   ⊢ (𝜑 → 𝐵 ∈ ℝ)    &   ⊢ (𝜑 → 𝐶 ≠ 1)    &   ⊢ (𝜑 → (𝐶↑𝑐𝐴) = (𝐶↑𝑐𝐵))    ⇒   ⊢ (𝜑 → 𝐴 = 𝐵)
Theorem	log11d 42824	The natural logarithm is one-to-one. (Contributed by SN, 25-Apr-2025.)
⊢ (𝜑 → 𝐴 ∈ ℂ)    &   ⊢ (𝜑 → 𝐵 ∈ ℂ)    &   ⊢ (𝜑 → 𝐴 ≠ 0)    &   ⊢ (𝜑 → 𝐵 ≠ 0)    ⇒   ⊢ (𝜑 → ((log‘𝐴) = (log‘𝐵) ↔ 𝐴 = 𝐵))
Theorem	rplog11d 42825	The natural logarithm is one-to-one on positive reals. (Contributed by SN, 25-Apr-2025.)
⊢ (𝜑 → 𝐴 ∈ ℝ+)    &   ⊢ (𝜑 → 𝐵 ∈ ℝ+)    ⇒   ⊢ (𝜑 → ((log‘𝐴) = (log‘𝐵) ↔ 𝐴 = 𝐵))
Theorem	rxp11d 42826	Real exponentiation is one-to-one with respect to the first argument. (Contributed by SN, 25-Apr-2025.)
⊢ (𝜑 → 𝐴 ∈ ℝ+)    &   ⊢ (𝜑 → 𝐵 ∈ ℝ+)    &   ⊢ (𝜑 → 𝐶 ∈ ℝ)    &   ⊢ (𝜑 → 𝐶 ≠ 0)    &   ⊢ (𝜑 → (𝐴↑𝑐𝐶) = (𝐵↑𝑐𝐶))    ⇒   ⊢ (𝜑 → 𝐴 = 𝐵)
21.30.4  Trigonometry and Calculus
Theorem	tanhalfpim 42827	The tangent of π / 2 minus a number is the cotangent, here represented by cos𝐴 / sin𝐴. (Contributed by SN, 2-Sep-2025.)
⊢ (𝜑 → 𝐴 ∈ ℂ)    &   ⊢ (𝜑 → (sin‘𝐴) ≠ 0)    ⇒   ⊢ (𝜑 → (tan‘((π / 2) − 𝐴)) = ((cos‘𝐴) / (sin‘𝐴)))
Theorem	sinpim 42828	Sine of a number subtracted from π. (Contributed by SN, 19-Nov-2025.)
⊢ (𝐴 ∈ ℂ → (sin‘(π − 𝐴)) = (sin‘𝐴))
Theorem	cospim 42829	Cosine of a number subtracted from π. (Contributed by SN, 19-Nov-2025.)
⊢ (𝐴 ∈ ℂ → (cos‘(π − 𝐴)) = -(cos‘𝐴))
Theorem	tan3rdpi 42830	The tangent of π / 3 is √3. (Contributed by SN, 2-Sep-2025.)
⊢ (tan‘(π / 3)) = (√‘3)
Theorem	sin2t3rdpi 42831	The sine of 2 · (π / 3) is (√3) / 2. (Contributed by SN, 19-Nov-2025.)
⊢ (sin‘(2 · (π / 3))) = ((√‘3) / 2)
Theorem	cos2t3rdpi 42832	The cosine of 2 · (π / 3) is -1 / 2. (Contributed by SN, 19-Nov-2025.)
⊢ (cos‘(2 · (π / 3))) = -(1 / 2)
Theorem	sin4t3rdpi 42833	The sine of 4 · (π / 3) is -(√3) / 2. (Contributed by SN, 19-Nov-2025.)
⊢ (sin‘(4 · (π / 3))) = -((√‘3) / 2)
Theorem	cos4t3rdpi 42834	The cosine of 4 · (π / 3) is -1 / 2. (Contributed by SN, 19-Nov-2025.)
⊢ (cos‘(4 · (π / 3))) = -(1 / 2)
Theorem	asin1half 42835	The arcsine of 1 / 2 is π / 6. (Contributed by SN, 31-Aug-2025.)
⊢ (arcsin‘(1 / 2)) = (π / 6)
Theorem	acos1half 42836	The arccosine of 1 / 2 is π / 3. (Contributed by SN, 31-Aug-2024.)
⊢ (arccos‘(1 / 2)) = (π / 3)
Theorem	dvun 42837	Condition for the union of the derivatives of two disjoint functions to be equal to the derivative of the union of the two functions. If 𝐴 and 𝐵 are open sets, this condition (dvun.n) is satisfied by isopn3i 23072. (Contributed by SN, 30-Sep-2025.)
⊢ 𝐽 = (𝐾 ↾t 𝑆)    &   ⊢ 𝐾 = (TopOpen‘ℂfld)    &   ⊢ (𝜑 → 𝑆 ⊆ ℂ)    &   ⊢ (𝜑 → 𝐹:𝐴⟶ℂ)    &   ⊢ (𝜑 → 𝐺:𝐵⟶ℂ)    &   ⊢ (𝜑 → 𝐴 ⊆ 𝑆)    &   ⊢ (𝜑 → 𝐵 ⊆ 𝑆)    &   ⊢ (𝜑 → (𝐴 ∩ 𝐵) = ∅)    &   ⊢ (𝜑 → (((int‘𝐽)‘𝐴) ∪ ((int‘𝐽)‘𝐵)) = ((int‘𝐽)‘(𝐴 ∪ 𝐵)))    ⇒   ⊢ (𝜑 → ((𝑆 D 𝐹) ∪ (𝑆 D 𝐺)) = (𝑆 D (𝐹 ∪ 𝐺)))
Theorem	redvmptabs 42838*	The derivative of the absolute value, for real numbers. (Contributed by SN, 30-Sep-2025.)
⊢ 𝐷 = (ℝ ∖ {0})    ⇒   ⊢ (ℝ D (𝑥 ∈ 𝐷 ↦ (abs‘𝑥))) = (𝑥 ∈ 𝐷 ↦ if(𝑥 < 0, -1, 1))
Theorem	readvrec2 42839*	The antiderivative of 1/x in real numbers, without using the absolute value function. (Contributed by SN, 1-Oct-2025.)
⊢ 𝐷 = (ℝ ∖ {0})    ⇒   ⊢ (ℝ D (𝑥 ∈ 𝐷 ↦ ((log‘(𝑥↑2)) / 2))) = (𝑥 ∈ 𝐷 ↦ (1 / 𝑥))
Theorem	readvrec 42840*	For real numbers, the antiderivative of 1/x is ln|x|. (Contributed by SN, 30-Sep-2025.)
⊢ 𝐷 = (ℝ ∖ {0})    ⇒   ⊢ (ℝ D (𝑥 ∈ 𝐷 ↦ (log‘(abs‘𝑥)))) = (𝑥 ∈ 𝐷 ↦ (1 / 𝑥))
Theorem	resuppsinopn 42841	The support of sin (df-supp 8108) restricted to the reals is an open set. (Contributed by SN, 7-Oct-2025.)
⊢ 𝐷 = {𝑦 ∈ ℝ ∣ (sin‘𝑦) ≠ 0}    ⇒   ⊢ 𝐷 ∈ (topGen‘ran (,))
Theorem	readvcot 42842*	Real antiderivative of cotangent. (Contributed by SN, 7-Oct-2025.)
⊢ 𝐷 = {𝑦 ∈ ℝ ∣ (sin‘𝑦) ≠ 0}    ⇒   ⊢ (ℝ D (𝑥 ∈ 𝐷 ↦ (log‘(abs‘(sin‘𝑥))))) = (𝑥 ∈ 𝐷 ↦ ((cos‘𝑥) / (sin‘𝑥)))
21.30.5  Independence of ax-mulcom This section mainly concerns the independence of ax-mulcom 11100, which is the only real and complex number axiom whose independence is open ( https://us.metamath.org/mpeuni/mmcomplex.html 11100). In particular, this is a combination of attempts to prove more and more properties of real and complex numbers without ax-mulcom 11100. Completing this direction would show that ax-mulcom 11100 is not independent. Alternatively, one could search for a model satisfying all axioms except ax-mulcom 11100, thus showing it is independent. A few models satisfying non-commutativity which only violate one other axiom are provided at https://gist.github.com/icecream17/933f95d820e0b8f1cab0d4293b68eaf9 11100. I conjecture that if it is possible to prove ax-mulcom 11100 from the other axioms, then all the other axioms are needed. In abstract terms, the symbol ℝ would have to correspond to an infinite non-commutative left-near-field with a Dedekind-complete order compatible with its ring operations. (Note: https://en.wikipedia.org/wiki/Near-field_(mathematics) 11100 does not require commutativity despite having "field" in the name.) Needless to say, this is a very undeveloped area of math. In addition, such a structure for ℝ would have to, together with the structure for the symbol ℂ, satisfy ax-resscn 11093, ax-icn 11095, ax-i2m1 11104, and most crucially ax-cnre 11109. None of the theorems in this section should be moved to main. If there is a naming conflict, feel free to add the prefix "sn-".
Syntax	cresub 42843	Real number subtraction.
class −ℝ
Definition	df-resub 42844*	Define subtraction between real numbers. This operator saves a few axioms over df-sub 11377 in certain situations. Theorem resubval 42845 shows its value, resubadd 42857 relates it to addition, and rersubcl 42856 proves its closure. It is the restriction of df-sub 11377 to the reals: subresre 42909. (Contributed by Steven Nguyen, 7-Jan-2023.)
⊢ −ℝ = (𝑥 ∈ ℝ, 𝑦 ∈ ℝ ↦ (℩𝑧 ∈ ℝ (𝑦 + 𝑧) = 𝑥))
Theorem	resubval 42845*	Value of real subtraction, which is the (unique) real 𝑥 such that 𝐵 + 𝑥 = 𝐴. (Contributed by Steven Nguyen, 7-Jan-2023.)
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 −ℝ 𝐵) = (℩𝑥 ∈ ℝ (𝐵 + 𝑥) = 𝐴))
Theorem	renegeulemv 42846*	Lemma for renegeu 42848 and similar. Derive existential uniqueness from existence. (Contributed by Steven Nguyen, 28-Jan-2023.)
⊢ (𝜑 → 𝐵 ∈ ℝ)    &   ⊢ (𝜑 → ∃𝑦 ∈ ℝ (𝐵 + 𝑦) = 𝐴)    ⇒   ⊢ (𝜑 → ∃!𝑥 ∈ ℝ (𝐵 + 𝑥) = 𝐴)
Theorem	renegeulem 42847*	Lemma for renegeu 42848 and similar. Remove a change in bound variables from renegeulemv 42846. (Contributed by Steven Nguyen, 28-Jan-2023.)
⊢ (𝜑 → 𝐵 ∈ ℝ)    &   ⊢ (𝜑 → ∃𝑦 ∈ ℝ (𝐵 + 𝑦) = 𝐴)    ⇒   ⊢ (𝜑 → ∃!𝑦 ∈ ℝ (𝐵 + 𝑦) = 𝐴)
Theorem	renegeu 42848*	Existential uniqueness of real negatives. (Contributed by Steven Nguyen, 7-Jan-2023.)
⊢ (𝐴 ∈ ℝ → ∃!𝑥 ∈ ℝ (𝐴 + 𝑥) = 0)
Theorem	rernegcl 42849	Closure law for negative reals. (Contributed by Steven Nguyen, 7-Jan-2023.)
⊢ (𝐴 ∈ ℝ → (0 −ℝ 𝐴) ∈ ℝ)
Theorem	renegadd 42850	Relationship between real negation and addition. (Contributed by Steven Nguyen, 7-Jan-2023.)
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → ((0 −ℝ 𝐴) = 𝐵 ↔ (𝐴 + 𝐵) = 0))
Theorem	renegid 42851	Addition of a real number and its negative. (Contributed by Steven Nguyen, 7-Jan-2023.)
⊢ (𝐴 ∈ ℝ → (𝐴 + (0 −ℝ 𝐴)) = 0)
Theorem	reneg0addlid 42852	Negative zero is a left additive identity. (Contributed by Steven Nguyen, 7-Jan-2023.)
⊢ (𝐴 ∈ ℝ → ((0 −ℝ 0) + 𝐴) = 𝐴)
Theorem	resubeulem1 42853	Lemma for resubeu 42855. A value which when added to zero, results in negative zero. (Contributed by Steven Nguyen, 7-Jan-2023.)
⊢ (𝐴 ∈ ℝ → (0 + (0 −ℝ (0 + 0))) = (0 −ℝ 0))
Theorem	resubeulem2 42854	Lemma for resubeu 42855. A value which when added to 𝐴, results in 𝐵. (Contributed by Steven Nguyen, 7-Jan-2023.)
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 + ((0 −ℝ 𝐴) + ((0 −ℝ (0 + 0)) + 𝐵))) = 𝐵)
Theorem	resubeu 42855*	Existential uniqueness of real differences. (Contributed by Steven Nguyen, 7-Jan-2023.)
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → ∃!𝑥 ∈ ℝ (𝐴 + 𝑥) = 𝐵)
Theorem	rersubcl 42856	Closure for real subtraction. Based on subcl 11390. (Contributed by Steven Nguyen, 7-Jan-2023.)
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 −ℝ 𝐵) ∈ ℝ)
Theorem	resubadd 42857	Relation between real subtraction and addition. Based on subadd 11394. (Contributed by Steven Nguyen, 7-Jan-2023.)
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ) → ((𝐴 −ℝ 𝐵) = 𝐶 ↔ (𝐵 + 𝐶) = 𝐴))
Theorem	resubaddd 42858	Relationship between subtraction and addition. Based on subaddd 11521. (Contributed by Steven Nguyen, 8-Jan-2023.)
⊢ (𝜑 → 𝐴 ∈ ℝ)    &   ⊢ (𝜑 → 𝐵 ∈ ℝ)    &   ⊢ (𝜑 → 𝐶 ∈ ℝ)    ⇒   ⊢ (𝜑 → ((𝐴 −ℝ 𝐵) = 𝐶 ↔ (𝐵 + 𝐶) = 𝐴))
Theorem	resubf 42859	Real subtraction is an operation on the real numbers. Based on subf 11393. (Contributed by Steven Nguyen, 7-Jan-2023.)
⊢ −ℝ :(ℝ × ℝ)⟶ℝ
Theorem	repncan2 42860	Addition and subtraction of equals. Compare pncan2 11398. (Contributed by Steven Nguyen, 8-Jan-2023.)
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → ((𝐴 + 𝐵) −ℝ 𝐴) = 𝐵)
Theorem	repncan3 42861	Addition and subtraction of equals. Based on pncan3 11399. (Contributed by Steven Nguyen, 8-Jan-2023.)
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 + (𝐵 −ℝ 𝐴)) = 𝐵)
Theorem	readdsub 42862	Law for addition and subtraction. (Contributed by Steven Nguyen, 28-Jan-2023.)
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ) → ((𝐴 + 𝐵) −ℝ 𝐶) = ((𝐴 −ℝ 𝐶) + 𝐵))
Theorem	reladdrsub 42863	Move LHS of a sum into RHS of a (real) difference. Version of mvlladdd 11559 with real subtraction. (Contributed by Steven Nguyen, 8-Jan-2023.)
⊢ (𝜑 → 𝐴 ∈ ℝ)    &   ⊢ (𝜑 → 𝐵 ∈ ℝ)    &   ⊢ (𝜑 → (𝐴 + 𝐵) = 𝐶)    ⇒   ⊢ (𝜑 → 𝐵 = (𝐶 −ℝ 𝐴))
Theorem	reltsub1 42864	Subtraction from both sides of 'less than'. Compare ltsub1 11644. (Contributed by SN, 13-Feb-2024.)
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ) → (𝐴 < 𝐵 ↔ (𝐴 −ℝ 𝐶) < (𝐵 −ℝ 𝐶)))
Theorem	reltsubadd2 42865	'Less than' relationship between addition and subtraction. Compare ltsubadd2 11619. (Contributed by SN, 13-Feb-2024.)
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ) → ((𝐴 −ℝ 𝐵) < 𝐶 ↔ 𝐴 < (𝐵 + 𝐶)))
Theorem	resubcan2 42866	Cancellation law for real subtraction. Compare subcan2 11417. (Contributed by Steven Nguyen, 8-Jan-2023.)
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ) → ((𝐴 −ℝ 𝐶) = (𝐵 −ℝ 𝐶) ↔ 𝐴 = 𝐵))
Theorem	resubsub4 42867	Law for double subtraction. Compare subsub4 11425. (Contributed by Steven Nguyen, 14-Jan-2023.)
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ) → ((𝐴 −ℝ 𝐵) −ℝ 𝐶) = (𝐴 −ℝ (𝐵 + 𝐶)))
Theorem	rennncan2 42868	Cancellation law for real subtraction. Compare nnncan2 11429. (Contributed by Steven Nguyen, 14-Jan-2023.)
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ) → ((𝐴 −ℝ 𝐶) −ℝ (𝐵 −ℝ 𝐶)) = (𝐴 −ℝ 𝐵))
Theorem	renpncan3 42869	Cancellation law for real subtraction. Compare npncan3 11430. (Contributed by Steven Nguyen, 28-Jan-2023.)
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ) → ((𝐴 −ℝ 𝐵) + (𝐶 −ℝ 𝐴)) = (𝐶 −ℝ 𝐵))
Theorem	repnpcan 42870	Cancellation law for addition and real subtraction. Compare pnpcan 11431. (Contributed by Steven Nguyen, 19-May-2023.)
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ) → ((𝐴 + 𝐵) −ℝ (𝐴 + 𝐶)) = (𝐵 −ℝ 𝐶))
Theorem	reppncan 42871	Cancellation law for mixed addition and real subtraction. Compare ppncan 11434. (Contributed by SN, 3-Sep-2023.)
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ) → ((𝐴 + 𝐶) + (𝐵 −ℝ 𝐶)) = (𝐴 + 𝐵))
Theorem	resubidaddlidlem 42872	Lemma for resubidaddlid 42873. A special case of npncan 11413. (Contributed by Steven Nguyen, 8-Jan-2023.)
⊢ (𝜑 → 𝐴 ∈ ℝ)    &   ⊢ (𝜑 → 𝐵 ∈ ℝ)    &   ⊢ (𝜑 → 𝐶 ∈ ℝ)    &   ⊢ (𝜑 → (𝐴 −ℝ 𝐵) = (𝐵 −ℝ 𝐶))    ⇒   ⊢ (𝜑 → ((𝐴 −ℝ 𝐵) + (𝐵 −ℝ 𝐶)) = (𝐴 −ℝ 𝐶))
Theorem	resubidaddlid 42873	Any real number subtracted from itself forms a left additive identity. (Contributed by Steven Nguyen, 8-Jan-2023.)
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → ((𝐴 −ℝ 𝐴) + 𝐵) = 𝐵)
Theorem	resubdi 42874	Distribution of multiplication over real subtraction. (Contributed by Steven Nguyen, 3-Jun-2023.)
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ) → (𝐴 · (𝐵 −ℝ 𝐶)) = ((𝐴 · 𝐵) −ℝ (𝐴 · 𝐶)))
Theorem	re1m1e0m0 42875	Equality of two left-additive identities. See resubidaddlid 42873. Uses ax-i2m1 11104. (Contributed by SN, 25-Dec-2023.)
⊢ (1 −ℝ 1) = (0 −ℝ 0)
Theorem	sn-00idlem1 42876	Lemma for sn-00id 42879. (Contributed by SN, 25-Dec-2023.)
⊢ (𝐴 ∈ ℝ → (𝐴 · (0 −ℝ 0)) = (𝐴 −ℝ 𝐴))
Theorem	sn-00idlem2 42877	Lemma for sn-00id 42879. (Contributed by SN, 25-Dec-2023.)
⊢ ((0 −ℝ 0) ≠ 0 → (0 −ℝ 0) = 1)
Theorem	sn-00idlem3 42878	Lemma for sn-00id 42879. (Contributed by SN, 25-Dec-2023.)
⊢ ((0 −ℝ 0) = 1 → (0 + 0) = 0)
Theorem	sn-00id 42879	00id 11319 proven without ax-mulcom 11100 but using ax-1ne0 11105. (Though note that the current version of 00id 11319 can be changed to avoid ax-icn 11095, ax-addcl 11096, ax-mulcl 11098, ax-i2m1 11104, ax-cnre 11109. Most of this is by using 0cnALT3 42738 instead of 0cn 11134). (Contributed by SN, 25-Dec-2023.) (Proof modification is discouraged.)
⊢ (0 + 0) = 0
Theorem	re0m0e0 42880	Real number version of 0m0e0 12294 proven without ax-mulcom 11100. (Contributed by SN, 23-Jan-2024.)
⊢ (0 −ℝ 0) = 0
Theorem	readdlid 42881	Real number version of addlid 11327. (Contributed by SN, 23-Jan-2024.)
⊢ (𝐴 ∈ ℝ → (0 + 𝐴) = 𝐴)
Theorem	sn-addlid 42882	addlid 11327 without ax-mulcom 11100. (Contributed by SN, 23-Jan-2024.)
⊢ (𝐴 ∈ ℂ → (0 + 𝐴) = 𝐴)
Theorem	remul02 42883	Real number version of mul02 11322 proven without ax-mulcom 11100. (Contributed by SN, 23-Jan-2024.)
⊢ (𝐴 ∈ ℝ → (0 · 𝐴) = 0)
Theorem	sn-0ne2 42884	0ne2 12381 without ax-mulcom 11100. (Contributed by SN, 23-Jan-2024.)
⊢ 0 ≠ 2
Theorem	remul01 42885	Real number version of mul01 11323 proven without ax-mulcom 11100. (Contributed by SN, 23-Jan-2024.)
⊢ (𝐴 ∈ ℝ → (𝐴 · 0) = 0)
Theorem	sn-remul0ord 42886	A product is zero iff one of its factors are zero. (Contributed by SN, 24-Nov-2025.)
⊢ (𝜑 → 𝐴 ∈ ℝ)    &   ⊢ (𝜑 → 𝐵 ∈ ℝ)    ⇒   ⊢ (𝜑 → ((𝐴 · 𝐵) = 0 ↔ (𝐴 = 0 ∨ 𝐵 = 0)))
Theorem	resubid 42887	Subtraction of a real number from itself (compare subid 11411). (Contributed by SN, 23-Jan-2024.)
⊢ (𝐴 ∈ ℝ → (𝐴 −ℝ 𝐴) = 0)
Theorem	readdrid 42888	Real number version of addrid 11324 without ax-mulcom 11100. (Contributed by SN, 23-Jan-2024.)
⊢ (𝐴 ∈ ℝ → (𝐴 + 0) = 𝐴)
Theorem	resubid1 42889	Real number version of subid1 11412 without ax-mulcom 11100. (Contributed by SN, 23-Jan-2024.)
⊢ (𝐴 ∈ ℝ → (𝐴 −ℝ 0) = 𝐴)
Theorem	renegneg 42890	A real number is equal to the negative of its negative. Compare negneg 11442. (Contributed by SN, 13-Feb-2024.)
⊢ (𝐴 ∈ ℝ → (0 −ℝ (0 −ℝ 𝐴)) = 𝐴)
Theorem	readdcan2 42891	Commuted version of readdcan 11318 without ax-mulcom 11100. (Contributed by SN, 21-Feb-2024.)
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ) → ((𝐴 + 𝐶) = (𝐵 + 𝐶) ↔ 𝐴 = 𝐵))
Theorem	renegid2 42892	Commuted version of renegid 42851. (Contributed by SN, 4-May-2024.)
⊢ (𝐴 ∈ ℝ → ((0 −ℝ 𝐴) + 𝐴) = 0)
Theorem	remulneg2d 42893	Product with negative is negative of product. (Contributed by SN, 25-Jan-2025.)
⊢ (𝜑 → 𝐴 ∈ ℝ)    &   ⊢ (𝜑 → 𝐵 ∈ ℝ)    ⇒   ⊢ (𝜑 → (𝐴 · (0 −ℝ 𝐵)) = (0 −ℝ (𝐴 · 𝐵)))
Theorem	sn-it0e0 42894	Proof of it0e0 12398 without ax-mulcom 11100. Informally, a real number times 0 is 0, and ∃𝑟 ∈ ℝ𝑟 = i · 𝑠 by ax-cnre 11109 and renegid2 42892. (Contributed by SN, 30-Apr-2024.)
⊢ (i · 0) = 0
Theorem	sn-negex12 42895*	A combination of cnegex 11325 and cnegex2 11326, this proof takes cnre 11139 𝐴 = 𝑟 + i · 𝑠 and shows that i · -𝑠 + -𝑟 is both a left and right inverse. (Contributed by SN, 5-May-2024.) (Proof shortened by SN, 4-Jul-2025.)
⊢ (𝐴 ∈ ℂ → ∃𝑏 ∈ ℂ ((𝐴 + 𝑏) = 0 ∧ (𝑏 + 𝐴) = 0))
Theorem	sn-negex 42896*	Proof of cnegex 11325 without ax-mulcom 11100. (Contributed by SN, 30-Apr-2024.)
⊢ (𝐴 ∈ ℂ → ∃𝑏 ∈ ℂ (𝐴 + 𝑏) = 0)
Theorem	sn-negex2 42897*	Proof of cnegex2 11326 without ax-mulcom 11100. (Contributed by SN, 5-May-2024.)
⊢ (𝐴 ∈ ℂ → ∃𝑏 ∈ ℂ (𝑏 + 𝐴) = 0)
Theorem	sn-addcand 42898	addcand 11347 without ax-mulcom 11100. Note how the proof is almost identical to addcan 11328. (Contributed by SN, 5-May-2024.)
⊢ (𝜑 → 𝐴 ∈ ℂ)    &   ⊢ (𝜑 → 𝐵 ∈ ℂ)    &   ⊢ (𝜑 → 𝐶 ∈ ℂ)    ⇒   ⊢ (𝜑 → ((𝐴 + 𝐵) = (𝐴 + 𝐶) ↔ 𝐵 = 𝐶))
Theorem	sn-addrid 42899	addrid 11324 without ax-mulcom 11100. (Contributed by SN, 5-May-2024.)
⊢ (𝐴 ∈ ℂ → (𝐴 + 0) = 𝐴)
Theorem	sn-addcan2d 42900	addcan2d 11348 without ax-mulcom 11100. (Contributed by SN, 5-May-2024.)
⊢ (𝜑 → 𝐴 ∈ ℂ)    &   ⊢ (𝜑 → 𝐵 ∈ ℂ)    &   ⊢ (𝜑 → 𝐶 ∈ ℂ)    ⇒   ⊢ (𝜑 → ((𝐴 + 𝐶) = (𝐵 + 𝐶) ↔ 𝐴 = 𝐵))