0

I have written the following code:

\documentclass[12pt]{article}  
\usepackage{amsmath}  
\usepackage{amssymb}   
\usepackage{amsthm}  
\newtheorem{theorem}{Theorem}  
\newtheorem{lemma}{Lemma}  

\begin{document}  

\begin{lemma}   
My lemma  
\end{lemma}   

\begin{Proof}  
My proof  
\end{Proof}  

\end{document}  

It shows the following error

! LaTeX Error: Environment Proof undefined.  
See the LaTeX manual or LaTeX Companion for explanation.  
Type H <return> for immediate help.  
...  
l.15 \begin{Proof}  
Your command was ignored.  
Type I <command> <return> to replace it with another command,  
or <return> to continue without it.  
! LaTeX Error: \begin{document} ended by \end{Proof}.  
See the LaTeX manual or LaTeX Companion for explanation.  
Type H <return> for immediate help.  
...  
l.17 \end{Proof}  
Your command was ignored.  
Type I <command> <return> to replace it with another command,  
or <return> to continue without it.

Please help.

  • 2
    Welcome! It should be \begin{proof} and \end{proof}. LaTeX commands are case sensitive. – egreg Dec 20 '16 at 10:39
  • Case sensitive was the problem Proof should be proof. Please try with \begin{proof}My Proof\end{proof} – Saravanan Dec 20 '16 at 10:40
2

Case sensitivity is the problem: Proof should be proof. Please try with

\begin{proof}
My Proof
\end{proof}

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.