X-Git-Url: https://git.enpas.org/?a=blobdiff_plain;f=presentation.tex;fp=presentation.tex;h=1089ae6d3370fd8806f05c118936f10b0ccda34e;hb=df78daffd508f40f39777d37db16562007b2ed12;hp=3728511aebdea18f9e34abaaf7fb702f3637f80d;hpb=e319c3d9b3de84af2608cfbee8a3a7cbdba19615;p=bitonic-mengthesis.git diff --git a/presentation.tex b/presentation.tex index 3728511..1089ae6 100644 --- a/presentation.tex +++ b/presentation.tex @@ -366,13 +366,13 @@ \begin{frame} \frametitle{How do we type check this thing?} + \[\text{Is\ } \myfun{non-empty}\myappsp(3 \mycons \mynil) \text{\ the same as\ } \myunit\text{?}\] + Or in other words, is + \[ \mytt : \myunit \] + A valid argument to \[ \myfun{head} \myappsp (3 \mycons \mynil) : \myfun{non-empty}\myappsp(3 \mycons \mynil) \myarr \mynat \] - Is it the case that - \[ \mytt : \myfun{non-empty}\myappsp(3 \mycons \mynil) \] - Or - \[ \myfun{head} \myappsp (3 \mycons \mynil) : \myunit \myarr \mynat \] Yes: to typecheck, we reduce terms fully (to their \emph{normal form}) before comparing: @@ -443,10 +443,6 @@ Without the $\myb{l}$ we cannot compute, so we are stuck with \] Which is what we want. The interesting part is how to make the system compute nicely. - - This extends to other structures (tuples, inductive types, \dots). - Moreover, if we can deem two \emph{types} equal, we can \emph{coerce} - values from one to the other. \end{frame} \begin{frame} @@ -584,16 +580,6 @@ Without the $\myb{l}$ we cannot compute, so we are stuck with Conversely, when we use eliminators the type can be inferred. \end{frame} -\begin{frame} - \frametitle{Bidirectional type checking} - - This technique is known as \emph{bidirectional} type checking---some - terms get \emph{checked}, some terms \emph{infer} types. - - Usually used for pre-defined types or core calculi, \mykant\ extends - to user-defined types. -\end{frame} - \begin{frame} \frametitle{OTT + user defined types} @@ -622,9 +608,9 @@ Without the $\myb{l}$ we cannot compute, so we are stuck with For example we have that \[ \begin{array}{@{}l} - (\myb{x_1} {:} \mytya_1) \myarr \mytyb_1 \myeq (\myb{x_2} {:} \mytya_2) \myarr \mytyb_2 \myred \\ - \myind{2} \mytya_1 \myeq \mytya_2 \myand - ((\myb{x_1} : \mytya_1) \myarr (\myb{x_2} : \mytya_2) \myarr \mytyb_1[\myb{x_1}] \myeq \mytyb_2[\myb{x_2}]) + \myjm{(\myb{x_1} {:} \mytya_1) \myarr \mytyb_1}{\mytyp}{(\myb{x_2} {:} \mytya_2) \myarr \mytyb_2}{\mytyp} \myred \\ + \myind{2} \myjm{\mytya_1}{\mytyp}{\mytya_2}{\mytyp} \myand \\ + \myind{2} ((\myb{x_1} : \mytya_1) \myarr (\myb{x_2} : \mytya_2) \myarr \myjm{\myb{x_1}}{\mytya_1}{\myb{x_2}}{\mytya_2} \myarr \mytyb_1[\myb{x_1}] \myeq \mytyb_2[\myb{x_2}]) \end{array} \] @@ -632,12 +618,31 @@ Without the $\myb{l}$ we cannot compute, so we are stuck with submitting... but I have a fix. \end{frame} +\begin{frame} + \frametitle{Bonus! WebSocket prompt} + \url{http://bertus.mazzo.li}, go DDOS it! + + \includegraphics[width=\textwidth]{web-prompt.png} +\end{frame} + \begin{frame} \begin{center} {\Huge Demo} \end{center} \end{frame} +\begin{frame} + \frametitle{What have we done?} + + \begin{itemize} + \item A small theorem prover for intuitionistic logic, featuring: + \item Inductive data and record types; + \item A cumulative, implicit type hierarchy; + \item Partial type inference---bidirectional type checking; + \item Observational equality---coming soon to the implementation. + \end{itemize} +\end{frame} + \begin{frame} \frametitle{Further work}