Argthtjtr

I believe that usually you explicitly tell cleveref what to call your label using crefname{type}{singular}{plural}, this doen't work however as here "type" has to be the name of the counter (I believe). I've also tried using label[type]{label} to no avail.
Is there any way to accomplish two environments sharing a counter, but have cleveref be able to distinguish between them? (Or is there maybe some way to use two counters, but for them always to be equal/dependent as to accomplish the same effect?)

Below is an example:

documentclass{article}

usepackage[colorlinks, linkcolor=blue]{hyperref} 

usepackage[noabbrev, capitalise]{cleveref}

usepackage{tikz}



%new theorem environment

newcounter{theo}[section]setcounter{theo}{0}

renewcommand{thetheo}{arabic{section}.arabic{theo}}

newenvironment{theo}{%

refstepcounter{theo}%

tikz[baseline=(current bounding box.east),outer sep=0pt]

node[anchor=east,rectangle,fill=green!20]

{strut textbf{Theorem~thetheo.}};

newline

}



crefname{theo}{Theorem}{Theorems}



%new lemma environment

newenvironment{lem}{%

refstepcounter{theo}

tikz[baseline=(current bounding box.east),outer sep=0pt]

node[anchor=east,rectangle,fill=blue!20]

{strut textbf{Lemma~thetheo.}};

newline

}



begin{document}

begin{theo}label{thrm}

Just some text.

end{theo}



begin{lem}label{lm1}

Just some more text.

end{lem}



begin{lem}label[Lemma]{lm2}

Just some more text.

end{lem}



noindent

cref{thrm}\ %give Theorem 0.1

cref{lm1}\ %give Lemma 0.2

cref{lm2}\ %give Lemma 0.3

end{document}

At the bottom of the example I use cref three times. In a comment I display the desired output.
Here I used crefname{theo}{Theorem}{Theorems} to give the "theo"-environment the correct name, as you can see then the "lem"-environment gets the same name, when referred to. The second time I use the "lem"-environment, I label it using label[Lemma]{lm2}, which turns out not to have the desired effect.

(Note: The code that uses tikz is not relevant, I added it as a small justification for not using the newtheorem command instead.)

You can allocate lem and theo to the same count register (with care:-)

documentclass{article}

usepackage[colorlinks, linkcolor=blue]{hyperref} 

usepackage[noabbrev, capitalise]{cleveref}

usepackage{tikz}



%new theorem environment

newcounter{theo}[section]setcounter{theo}{0}

renewcommand{thetheo}{arabic{section}.arabic{theo}}

newenvironment{theo}{%

refstepcounter{theo}%

tikz[baseline=(current bounding box.east),outer sep=0pt]

node[anchor=east,rectangle,fill=green!20]

{strut textbf{Theorem~thetheo.}};

newline%BADNESS 10000!!!!!

}



makeatletter

letc@lemc@theo

%now def not let so it picks up current value

defp@lem{p@theo}

defthelem{thetheo}

makeatother

crefname{theo}{Theorem}{Theorems}

crefname{lem}{Lemma}{Lemmas}



%new lemma environment

newenvironment{lem}{%

refstepcounter{lem}%

tikz[baseline=(current bounding box.east),outer sep=0pt]

node[anchor=east,rectangle,fill=blue!20]

{strut textbf{Lemma~thetheo.}};

newline%BADNESS 10000!!!!!

}



begin{document}

begin{theo}label{thrm}

Just some text.

end{theo}



begin{lem}label{lm1}

Just some more text.

end{lem}



begin{lem}label{lm2}

Just some more text.

end{lem}



noindent

cref{thrm}\ %give Theorem 0.1

cref{lm1}\ %give Lemma 0.2

cref{lm2}\ %give Lemma 0.3

end{document}

No need for any programming contortions -- just load either the amsthm or the ntheorem package before both hyperref and cleveref, and then define the theorem-like environments the usual way. In particular, it's perfectly ok for several theorem-like environments to share the same counter (theo in the following code):

documentclass{article}



usepackage{amsthm} %or: usepackage{ntheorem}

usepackage[colorlinks, linkcolor=blue]{hyperref} 

usepackage[noabbrev, capitalise]{cleveref}



% two new theorem-like environments

newtheorem{theo}{Theorem}[section] % subordinate 'theo' cntr to 'section' cntr

newtheorem{lem}[theo]{Lemma} % make 'lem' and 'theo' share same cntr



crefname{theo}{Theorem}{Theorems}

crefname{lem}{Lemma}{Lemmas}



begin{document}

setcounter{section}{2} % just for this example



begin{theo}label{thrm}Just some text.end{theo}

begin{lem}label{lm1}Just some more text.end{lem}

begin{lem}label{lm2}Still more text.end{lem}



cref{thrm} dots



cref{lm1,lm2} dots

end{document}