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Contents 
User account
 Use "FirstName LastName" as Username.
 Use a valid email address.
Conventions
 Use English only, even for comments, discussions, ...
 Use == Header == for higherlevel headers, do not use only one equals sign on a side.
Notations
For uniformity, use the common notations when they are already defined, and add your notations to the notations page when you introduce new ones.
Definitions and theorems
For theoremstyle environments, use the appropriate predefined templates: Definition, Theorem, Proposition, Lemma, Corollary (with an optional parameter "title"). Additional templates are Proof for proofs and Remark for remarks.
{{Definitiontitle=ConceptA new concept.}} {{TheoremThis is a nice concept.}} {{ProofLeft to the reader.}} {{RemarkReally nice, isn't it?}} 
Definition (Concept) A new concept. Theorem This is a nice concept. Proof. Left to the reader. Remark: Really nice, isn't it?

Mathematical typesetting
Formulas
 use the macros defined in the LLWiki LaTeX Style
Proofs
The syntax for proofs is based on the bussproofs.sty package, but available only through a sugarcoated specific to llwiki. Here is an example:
\AxRule{} \VdotsRule{s}{{}\vdash\Gamma,A\imp B} \AxRule{} \VdotsRule{t}{{}\vdash\Gamma, A} \BinRule{{}\vdash \Gamma, B} \LabelRule{\rulename{modus ponens}} \DisplayProof \quad \longrightarrow_\beta \quad \AxRule{} \VdotsRule{s[t/x]}{{}\vdash\Gamma, B} \DisplayProof
A list of all available macros for proofs is available on the page for the LLWiki LaTeX package.
Set of rules
For a group of rules, separate rules on a line by \qquad and separate lines by <br />.
<math> \AxRule{\textit{Hyp}_1} \AxRule{\textit{Hyp}_2} \LabelRule{\rulename{Rule}_1} \BinRule{\textit{Concl}} \DisplayProof \qquad \AxRule{\textit{Hyp}_1} \AxRule{\textit{Hyp}_2} \LabelRule{\rulename{Rule}_1} \BinRule{\textit{Concl}} \DisplayProof </math> <br /> <math> \AxRule{\textit{Hyp}_1} \AxRule{\textit{Hyp}_2} \LabelRule{\rulename{Rule}_3} \BinRule{\textit{Concl}} \DisplayProof \qquad \AxRule{\textit{Hyp}_1} \AxRule{\textit{Hyp}_2} \LabelRule{\rulename{Rule}_4} \BinRule{\textit{Concl}} \DisplayProof </math>