I am a beginner with amsthm, and I'm using cleveref for referencing the theorem s/definitions/lemmas. BTW, all of this is happening in beamer. On using \Cref{label} for definitions, lemmas, and everything else under the sun - I get something of the form Theorem <number>. Everything isn't a theorem! I want Definition <number> and Lemma <number> too. How can I fix this?
I also get this error:
Warning: hyperref package loaded with implicit=false option - disabling cleveref's hyperref support. This situation is not supported by cleveref, and there's no guarantee anything will work. You're on your own! on input line 2370.
\documentclass[aspectratio=169,xcolor=dvipsnames]{beamer}
\setbeamercovered{transparent}
\setbeamertemplate{theorems}[numbered]
\usetheme{CambridgeUS}
\usepackage{amsmath,amssymb,amsthm,amsfonts,amscd}
\usepackage{cleveref}
\usepackage{tikz}
\usepackage{parskip}
\usepackage{graphicx} % Allows including images
\usepackage{booktabs} % Allows the use of \toprule, \midrule and \bottomrule in tables
\usepackage{hyperref}
\theoremstyle{definition}
\numberwithin{theorem}{section}
\newtheorem{exercise}{Exercise}
\begin{definition}[Program]
\label{prog}
A program is a set of states in a labeled transition system.
\end{definition}
\begin{theorem}
Euler is the best mathematician.
\end{theorem}
\begin{lemma}
\label{xyz}
beamer is amazing.
\end{lemma}
We just saw \Cref{xyz} and \Cref{prog}.

latex beamer theorem numbering? Here's the first hit: https://tex.stackexchange.com/a/188393/3929, I'm pretty sure it is also mentioned in the beamer manual (not at pc so cannot test) – daleif Apr 21 '21 at 11:41