How statement and proof provenance work
The first chip identifies the source of the statement or construction; the second identifies the source of its local proof or verification.
- Literature-sourced: the exact statement appears in a cited source; only wording and notation differ.
- AI-adapted: a semantically identical restatement of literature-sourced material, modulo indexing, notation, and boundary cases adopted by the library.
- AI-generated: a genuinely novel statement formulated by AI, with no source for the claim itself.
These labels describe origin, not correctness: citations and verification chips remain separate evidence.
Bloch, Schottky, and the Picard Theorems — Examples
1 · Prerequisites
- Absolute and Conditional Convergence; Rearrangement; Products
- Analyticity of Holomorphic Functions; Liouville and Morera
- Arc Length and Rectifiable Curves
- Binary Operations, Monoids, Groups and Subgroups
- Bloch, Schottky, and the Picard Theorems
- Bounded Variation and the Riemann–Stieltjes Integral
- Compactness
- Compactness in Metric Spaces
- Completeness, Completion, and Uniform Continuity
- Complex Differentiability and the Cauchy–Riemann Equations
- Complex Power Series and Analytic Functions
- Conformal Mapping, Branches, and the Schwarz Lemma
- Connectedness
- Construction of the Natural Numbers
- Construction of the Real Numbers via Cauchy Sequences
- Construction of the Real Numbers via Dedekind Cuts
- Continuity, IVT, EVT, and Uniform Continuity
- Contour Integration
- Cosets, Index and Lagrange's Theorem
- Countability and Uncountability
- Divisibility, Euclidean Domains, Principal Ideal Domains and Unique Factorisation
- Filters and Ultrafilters
- Finite Counting, Factorials and Binomial Coefficients
- Foundations of the Real Numbers for Analysis
- Function Space Topologies and the Exponential Law
- Fundamental Trigonometric Identities
- Goursat's Theorem and Cauchy's Theorem in a Convex Domain
- Group Homomorphisms and the Isomorphism Theorems
- Ideals, Quotient Rings and the Isomorphism Theorems for Rings
- Isolated Singularities and Laurent Series
- Limits of Real Functions
- limsup, liminf, and Subsequential Limits
- Line Integrals and the Gradient Theorem
- Linear Independence, Bases and Dimension
- Linear Transformations, Rank-Nullity and Quotient Spaces
- Matrices, the Matrix of a Linear Map, and Change of Basis
- Metric Spaces
- Mixed Partials, Taylor Formulae, and Extrema
- Monotone Functions, Discontinuities, and Continuity Sets
- Monotone Sequences, Bolzano-Weierstrass, and Cauchy Completeness
- Normal Families and Montel's Theorem
- Normal Subgroups and Quotient Groups
- Order, Zorn's Lemma, and the Axiom of Choice
- Partitions of Unity and Paracompactness
- pi: the Equivalent Characterizations
- Polynomial Rings, the Division Algorithm and Roots
- Power Series and Real-Analytic Functions
- Properties of the Integral and the Working FTC
- Relations, Functions, and Quotients
- Rings, Subrings, Integral Domains and Fields
- Rⁿ as a Normed Space; Vector-Valued Functions
- Roots, Rational Powers, and Classical Inequalities
- Separation Axioms: the Hierarchy
- Sequences and Limits
- Sequences and Series of Functions; Uniform Convergence
- Series: Convergence and the Nonnegative Tests
- Simple Field Extensions and the Construction of the Complex Numbers
- Sine, Cosine, and the Definition of Pi
- Subspaces, Products, and Quotients
- Suprema and Infima
- The Argument Principle and Rouché's Theorem
- The Ascoli–Arzelà Theorem
- The Cantor Set, Baire Category, and Measure Zero in ℝ
- The Complex Exponential and Euler's Formula
- The Derivative and the Mean Value Theorems
- The Exponential Function
- The Fundamental Theorems of Calculus
- The Identity Theorem, the Maximum Principle and the Open Mapping Theorem
- The Inverse and Implicit Function Theorems
- The Logarithm and General Powers
- The Residue Theorem and the Evaluation of Real Integrals
- The Riemann Integral: Definition and Integrability
- The Riemann Mapping Theorem
- The Riemann Sphere and Möbius Transformations
- The Topology of Euclidean Space
- The Total Derivative in ℝᵐ → ℝⁿ
- The Winding Number and the Global Cauchy Theorem
- The ZFC Axioms and the Basic Set Constructions
- Topological Spaces and Continuity
- Topology of ℝ
- Vector Spaces, Linear Subspaces, Span and Direct Sums
2 · Summary
These examples make the Picard package concrete. The first records the explicit numerical bound produced by the elementary Bloch proof actually written on this page, the next specializes Schottky's theorem at a fixed center value, and the exponential examples show the sharpness of both Picard theorems.
The counterexample and false statements keep the holomorphic and meromorphic versions distinct: on the plane, a nonconstant meromorphic function may omit two sphere values, and Little Picard does not need any extra boundedness hypothesis.
3 · Logical flowchart
4 · Definitions, theorems and proofs
None yet.
5 · Examples, counterexamples and false statements
The elementary Bloch proof on this page yields the explicit lower bound 1/48
Example
The proof of Bloch's theorem gives the concrete universal estimate
Facts & Assumptions
Given: A holomorphic map with .
Bloch's theorem on this page proves (Bloch's theorem).
Verification
Fact [L1] gives the lower bound for every normalized holomorphic disc map.
Applying step 1.1 to the present function is exactly the stated example.
Schottky's theorem applied to a disc map with center value 1/2
Example
For each there is a constant such that every holomorphic with satisfies
Facts & Assumptions
Given: A radius and a holomorphic map with .
Schottky's theorem supplies a bound depending only on the center modulus and the target radius (Schottky's theorem).
Verification
Apply [L1] with . This gives a constant depending only on .
The constant from step 1.1 works for the present function, so one may take .
The exponential function omits exactly zero and shows little Picard is sharp
Example
The exponential function is entire, omits exactly the value , and therefore shows that Little Picard's "at most one omitted finite value" is sharp.
Facts & Assumptions
Given: The complex exponential function.
The exponential is entire (The complex exponential is entire and its complex derivative is itself).
Its image is exactly (The complex exponential maps onto ).
Little Picard allows at most one omitted finite value (Little Picard theorem).
Verification
Facts [L1] and [L2] show that is a nonconstant entire function whose omitted finite-value set is exactly .
Fact [L3] says no nonconstant entire function can omit two finite values, while step 1.1 exhibits one omitting exactly one. Therefore the bound in Little Picard is sharp.
The function e^(1/z) omits zero and takes every nonzero value infinitely often near the origin
Example
The function
on omits and takes every nonzero value infinitely often near .
Facts & Assumptions
Given: The punctured-disc function .
The exponential maps onto (The complex exponential maps onto ).
Its fibres are the translates (, and exactly when ).
Verification
Since the exponential never vanishes, never equals on the punctured disc.
Fix . By [L1] and [L2], choose with ; then every number is another logarithm of . For every integer with , set . At most one integer is excluded, while all the remaining satisfy and as . Thus every nonzero value occurs infinitely often near .
Therefore Great Picard is sharp: one finite exceptional value can occur, namely .
The exponential function omits 0 and infinity as a meromorphic map on the plane
Statement refuted
A nonconstant meromorphic function on omits at most one sphere value.
Facts & Assumptions
Given: The exponential function regarded as a meromorphic map .
The exponential is entire (The complex exponential is entire and its complex derivative is itself).
Its image is (The complex exponential maps onto ).
Counterexample
Fact [L1] makes meromorphic on with no poles, and [L2] identifies its image as .
As a sphere-valued map, the omitted values are therefore and . Since is nonconstant, this refutes the claim that at most one sphere value can be omitted.
FALSE: little Picard needs a boundedness hypothesis
Statement
Little Picard's theorem needs an additional boundedness assumption on the entire function.
Facts & Assumptions
Given: Little Picard's theorem.
A nonconstant entire function omits at most one finite value (Little Picard theorem).
Refutation
Fact [L1] already states the omitted-value conclusion for every nonconstant entire function, with no boundedness hypothesis.
Therefore the asserted extra boundedness assumption is false.
FALSE: a nonconstant meromorphic function on the plane omits at most one sphere value
Statement
A nonconstant meromorphic function on omits at most one value of .
Facts & Assumptions
Given: The meromorphic exponential counterexample.
The exponential meromorphic map on omits and (The exponential function omits 0 and infinity as a meromorphic map on the plane).
Refutation
Fact [L1] is already a nonconstant meromorphic function on omitting two sphere values.
Therefore the claim "at most one sphere value" is false.