1 \documentclass[a4paper,draft]{article}
8 \newcommand{\MATITA}{\ding{46}\textsf{\textbf{Matita}}}
10 \title{Continuationals semantics for \MATITA}
11 \author{Claudio Sacerdoti Coen \quad Enrico Tassi \quad Stefano Zacchiroli \\
12 \small Department of Computer Science, University of Bologna \\
13 \small Mura Anteo Zamboni, 7 -- 40127 Bologna, ITALY \\
14 \small \{\texttt{sacerdot}, \texttt{tassi}, \texttt{zacchiro}\}\texttt{@cs.unibo.it}}
16 \newcommand{\MATHIT}[1]{\ensuremath{\mathit{#1}}}
17 \newcommand{\MATHTT}[1]{\ensuremath{\mathtt{#1}}}
19 \newcommand{\DOT}{\ensuremath{\mbox{\textbf{.}}}}
20 \newcommand{\SEMICOLON}{\ensuremath{\mbox{\textbf{;}}}}
21 \newcommand{\BRANCH}{\ensuremath{\mbox{\textbf{[}}}}
22 \newcommand{\SHIFT}{\ensuremath{\mbox{\textbf{\textbar}}}}
23 \newcommand{\POS}[1]{\ensuremath{#1\mbox{\textbf{:}}}}
24 \newcommand{\MERGE}{\ensuremath{\mbox{\textbf{]}}}}
25 \newcommand{\FOCUS}[1]{\ensuremath{\mathtt{focus}~#1}}
26 \newcommand{\ENDFOCUS}{\ensuremath{\mathtt{unfocus}}}
27 \newcommand{\SKIP}{\MATHTT{skip}}
28 \newcommand{\TACTIC}[1]{\ensuremath{\mathtt{tactic}~#1}}
30 \newcommand{\APPLY}[1]{\ensuremath{\mathtt{apply}~\mathit{#1}}}
32 \newcommand{\GOAL}{\MATHIT{goal}}
33 \newcommand{\SWITCH}{\MATHIT{switch}}
34 \newcommand{\LIST}{\MATHTT{list}}
35 \newcommand{\INT}{\MATHTT{int}}
36 \newcommand{\OPEN}{\MATHTT{Open}}
37 \newcommand{\CLOSED}{\MATHTT{Closed}}
39 \newcommand{\SEMOP}[1]{|[#1|]}
40 \newcommand{\TSEMOP}[1]{{}_t|[#1|]}
41 \newcommand{\SEM}[3][\xi]{\SEMOP{#2}_{{#1},{#3}}}
42 \newcommand{\ENTRY}[4]{\langle#1,#2,#3,#4\rangle}
43 \newcommand{\TSEM}[3]{\TSEMOP{#1}_{#2,#3}}
45 \newcommand{\GIN}[1][1]{\ensuremath{[s_{#1};\cdots;s_n]}}
47 \newcommand{\ZEROPOS}{\MATHIT{zero\_pos}}
48 \newcommand{\INITPOS}{\MATHIT{init\_pos}}
49 \newcommand{\ISFRESH}{\MATHIT{is\_fresh}}
50 \newcommand{\FILTER}{\MATHIT{filter}}
51 \newcommand{\FILTEROPEN}{\MATHIT{filter\_open}}
52 \newcommand{\ISOPEN}{\MATHIT{is\_open}}
53 \newcommand{\DEEPCLOSE}{\MATHIT{deep\_close}}
55 \newcommand{\BRANCHTAG}{\ensuremath{\mathtt{B}}}
56 \newcommand{\FOCUSTAG}{\ensuremath{\mathtt{S}}}
58 \newlength{\sidecondlen}
59 \setlength{\sidecondlen}{2cm}
70 S & ::= & & \mbox{(\textbf{continuationals})}\\
71 & & \TACTIC{T} & \mbox{(tactic)}\\[2ex]
72 & | & \DOT & \mbox{(dot)} \\
73 & | & \SEMICOLON & \mbox{(semicolon)} \\
74 & | & \BRANCH & \mbox{(branch)} \\
75 & | & \SHIFT & \mbox{(shift)} \\
76 & | & \POS{i} & \mbox{(relative positioning)} \\
77 & | & \MERGE & \mbox{(merge)} \\[2ex]
78 & | & \FOCUS{g_1,\dots,g_n} & \mbox{(absolute positioning)} \\
79 & | & \ENDFOCUS & \mbox{(unfocus)} \\[2ex]
80 T & : := & & \mbox{(\textbf{tactics})}\\
81 & & \SKIP & \mbox{(skip)} \\
82 & | & \mathtt{reflexivity} & \\
83 & | & \mathtt{apply}~t & \\
92 \SWITCH & = & \OPEN~\mathit{goal} ~ | ~ \CLOSED~\mathit{goal} & \\
93 \mathit{locator} & = & \INT\times\SWITCH & \\
94 \mathit{tag} & = & \BRANCHTAG ~ | ~ \FOCUSTAG \\[2ex]
96 \xi & = & (\INT\times\alpha)~\LIST& \mbox{(metasenv)} \\
97 \Gamma & = & \mathit{locator}~\LIST & \mbox{(context)} \\
98 \tau & = & \SWITCH~\LIST & \mbox{(todo)} \\
99 \kappa & = & \SWITCH~\LIST & \mbox{(dot's future)} \\[2ex]
101 \mathit{stack} & = & (\Gamma\times\tau\times\kappa\times\mathit{tag})~\LIST
104 \mathit{status} & = & \xi\times\mathit{stack} \\
108 \paragraph{Utilities}
110 \item \ZEROPOS: map $g -> 0, \OPEN~g$
111 \item \INITPOS: map $g -> i, \OPEN~g$
112 \item \ISFRESH: $\OPEN~g, 0 -> true | \_ -> false$
113 \item \FILTEROPEN: $G -> \FILTER(\ISOPEN,G)$
114 \item \DEEPCLOSE: prende uno stack ed un insieme di goal da chiudere, traversa
115 lo stack rimuovendo le occorrenze dei goal da $\tau$ e $\kappa$ e marcandole
119 \paragraph{Invariants}
121 \item $\forall \ENTRY{\Gamma}{\tau}{\kappa}{t}, \forall s \in\tau\cup\kappa,
122 \exists g, s = \OPEN~g$ (i goal in $\tau$ e $\kappa$ sono aperti)
123 \item la lista dei goal nel metasenv contiene tutti e soli i goal presenti
125 \item lo stack puo' contenere goal duplicati nel caso di uso della select
128 \subsection{Semantics}
132 \SEMOP{\cdot} & : & C -> \mathit{status} -> \mathit{status} &
133 \mbox{(continuationals semantics)} \\
134 \TSEMOP{\cdot} & : & T -> \xi -> \SWITCH ->
135 \xi\times\GOAL~\LIST\times\GOAL~\LIST & \mbox{(tactics semantics)} \\
141 \mathit{apply\_tac} & : & T -> \xi -> \GOAL ->
142 \xi\times\GOAL~\LIST\times\GOAL~\LIST
148 \TSEM{T}{\xi}{\OPEN~g} & = & \mathit{apply\_tac}(T,\xi,n) & T\neq\SKIP\\
149 \TSEM{\SKIP}{\xi}{\CLOSED~g} & = & \langle \xi, [], [g]\rangle &
156 \SEM{\TACTIC{T}}{\ENTRY{\GIN}{\tau}{\kappa}{t}::S}
160 \ENTRY{\ZEROPOS(G^o_n)}{\tau\setminus G^c_n}{\kappa\setminus G^o_n}{t}
161 :: \DEEPCLOSE(G^c_n,S)
165 \multicolumn{3}{l}{\hspace{\sidecondlen}\mathit{where} ~
168 \langle\xi_0, G^o_0, G^c_0\rangle & = & \langle\xi, [], []\rangle \\
169 \langle\xi_{i+1}, G^o_{i+1}, G^c_{i+1}\rangle
171 & \langle\xi_i, G^o_i, G^c_i\rangle
172 & s_{i+1}\in G^c_i \\
173 \langle\xi_{i+1}, G^o_{i+1}, G^c_{i+1}\rangle
175 & \langle\xi, (G^o_i\setminus G^c)\cup G^o, G^c_i\cup G^c\rangle
176 & s_{i+1}\not\in G^c_i \\[1ex]
177 & & \mathit{where} ~ \langle\xi,G^o,G^c\rangle=\TSEM{T}{\xi_i}{s_{i+1}}
184 \SEM{~\DOT~}{\ENTRY{\Gamma}{\tau}{\kappa}{t}::S}
186 & \langle \xi, \ENTRY{s_1}{\tau}{\GIN[2]\cup\kappa}{t}::S \rangle
188 & & \mathrm{where} ~ \FILTEROPEN(\Gamma)=\GIN
191 \SEM{~\DOT~}{\ENTRY{[]}{\tau}{s::\kappa}{t}::S}
193 & \langle \xi, \ENTRY{\Gamma}{\tau}{\kappa}{t}::S \rangle
196 \SEM{~\SEMICOLON~}{S} & = & \langle \xi, S \rangle \\[1ex]
198 \SEM{~\BRANCH~}{\ENTRY{\GIN}{\tau}{\kappa}{t}::S}
201 & \langle\xi, \ENTRY{s_1'}{[]}{[]}{\BRANCHTAG}
202 ::\ENTRY{[s_2';\cdots;s_n']}{\tau}{\kappa}{t}::S
204 & & \mathrm{where} ~ n\geq 2 ~ \land ~ \INITPOS(\GIN)=[s_1';\cdots;s_n']
208 {\ENTRY{\Gamma}{\tau}{\kappa}{\BRANCHTAG}::\ENTRY{\GIN}{\tau'}{\kappa'}{t}::S}
211 \xi, \ENTRY{s_1}{[]}{[]}{\BRANCHTAG}
212 ::\ENTRY{\GIN[2]}{\tau'\cup\FILTEROPEN(\Gamma)}{\kappa'}{t}::S
217 {\ENTRY{[s]}{[]}{[]}{\BRANCHTAG}::\ENTRY{\Gamma'}{\tau'}{\kappa'}{t'}::S}
219 & \langle \xi, \ENTRY{s_i}{[]}{[]}{\BRANCHTAG}
220 ::\ENTRY{s_i :: (\Gamma'\setminus [s_i])}{\tau'}{\kappa'}{t'}::S \rangle
222 & & \mathrm{where} ~ \langle i,s'\rangle = s_i\in \Gamma'~\land~\ISFRESH(s)
226 {\ENTRY{\Gamma}{\tau}{\kappa}{\BRANCHTAG}
227 ::\ENTRY{\Gamma'}{\tau'}{\kappa'}{t'}::S}
229 & \langle \xi, \ENTRY{s_i}{[]}{[]}{\BRANCHTAG}
230 ::\ENTRY{\Gamma'\setminus [s_i]}{\tau'\cup\FILTEROPEN(\Gamma)}{\kappa'}{t'}::S
233 & & \mathrm{where} ~ \langle i, s'\rangle = s_i\in \Gamma'
237 {\ENTRY{\Gamma}{\tau}{\kappa}{\BRANCHTAG}::\ENTRY{\Gamma'}{\tau'}{\kappa'}{t'}
241 \ENTRY{\tau\cup\FILTEROPEN(\Gamma)\cup\Gamma'\cup\kappa}{\tau'}{\kappa'}{t'}
246 \SEM{\FOCUS{g_1,\dots,g_n}}{S}
248 & \langle \xi, \ENTRY{[\OPEN~g_1;\cdots;\OPEN~g_n]}{[]}{[]}{\FOCUSTAG}::S
252 \forall ~ i=1,\dots,n,~\exists~\alpha_i,n_i,~\langle n_i,\alpha_i\rangle\in\xi
255 \SEM{\ENDFOCUS}{\ENTRY{[]}{[]}{[]}{\FOCUSTAG}::S}
257 & \langle \xi, S\rangle \\[2ex]