hol88-library-source 2.02.19940316-31 / usr / share / hol88-2.02.19940316 / Library / pair / syn.ml

This file is indexed.

/usr/share/hol88-2.02.19940316/Library/pair/syn.ml is in hol88-library-source 2.02.19940316-31.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below. 

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
% --------------------------------------------------------------------- %
% 		Copyright (c) Jim Grundy 1992				%
%               All rights reserved                                     %
%									%
% Jim Grundy, hereafter referred to as `the Author', retains the	%
% copyright and all other legal rights to the Software contained in	%
% this file, hereafter referred to as `the Software'.			%
% 									%
% The Software is made available free of charge on an `as is' basis.	%
% No guarantee, either express or implied, of maintenance, reliability	%
% or suitability for any purpose is made by the Author.			%
% 									%
% The user is granted the right to make personal or internal use	%
% of the Software provided that both:					%
% 1. The Software is not used for commercial gain.			%
% 2. The user shall not hold the Author liable for any consequences	%
%    arising from use of the Software.					%
% 									%
% The user is granted the right to further distribute the Software	%
% provided that both:							%
% 1. The Software and this statement of rights is not modified.		%
% 2. The Software does not form part or the whole of a system 		%
%    distributed for commercial gain.					%
% 									%
% The user is granted the right to modify the Software for personal or	%
% internal use provided that all of the following conditions are	%
% observed:								%
% 1. The user does not distribute the modified software. 		%
% 2. The modified software is not used for commercial gain.		%
% 3. The Author retains all rights to the modified software.		%
%									%
% Anyone seeking a licence to use this software for commercial purposes	%
% is invited to contact the Author.					%
% --------------------------------------------------------------------- %
% CONTENTS: functions on the syntax of paired abstractions and          %
%           quantifications.                                            %
% --------------------------------------------------------------------- %
%$Id: syn.ml,v 3.1 1993/12/07 14:42:10 jg Exp $%

% ===================================================================== %
% Constructors for paired HOL syntax.                                   %
% ===================================================================== %

let mk_pabs =
    let mk_uncurry cf =
	let tycf = type_of cf in
	let uncurry_type ty =
	    let (tycon1, [tya; tyb]) = (dest_type ty) in
	    let (tycon2, [tyba; tybb]) = (dest_type tyb) in
		assert (curry $= `fun`) tycon1 ;
		assert (curry $= `fun`) tycon2 ;
		mk_type (`fun`, [mk_type(`prod`,[tya;tyba]); tybb ])
	in
	    mk_comb
	    (   mk_const(`UNCURRY`,mk_type(`fun`,[tycf;uncurry_type tycf])) ,
		cf                                                          )
    in
    letrec mpa (p,t) =
	if is_var p then
	    mk_abs (p, t)
	else % is_pair p %
	    let (v1,v2) = dest_pair p in
		mk_uncurry (mpa (v1, (mpa (v2, t))))
    in
	\pt. mpa pt ? failwith `mk_pabs`;;

let mk_pforall (x,t) =
    let ty = type_of x in
    let allty = mk_type(`fun`,[mk_type(`fun`,[ty;bool_ty]);bool_ty]) in
	mk_comb(mk_const(`!`,allty),mk_pabs(x,t)) ? failwith `mk_pforall`;;

let mk_pexists (x,t) =
    let ty = type_of x in
    let exty = mk_type(`fun`,[mk_type(`fun`,[ty;bool_ty]);bool_ty]) in
	mk_comb(mk_const(`?`,exty),mk_pabs(x,t)) ? failwith `mk_pexists`;;

let mk_pselect (x,t) =
    let ty = type_of x in
    let selty = mk_type(`fun`,[mk_type(`fun`,[ty;bool_ty]);ty]) in
	mk_comb(mk_const(`@`, selty), mk_pabs(x,t)) ? failwith `mk_pselect`;;

% ===================================================================== %
% Destructors for paired HOL syntax.                                    %
% ===================================================================== %

letrec dest_pabs tm =
    (if (is_abs tm) then
	dest_abs tm
    else if fst (dest_const (rator tm)) = `UNCURRY` then
	let (v1,b1) = dest_pabs (rand tm) in
	let (v2,b2) = dest_pabs b1 in
	    (mk_pair(v1,v2), b2)
    else fail) ? failwith `dest_pabs`;;

let dest_pforall =
    let check = assert (\c. fst(dest_const c) = `!`) in
    \tm. (let (_,b) = (check # I) (dest_comb tm) in dest_pabs b) ?
	failwith `dest_pforall`;;

let dest_pexists =
    let check = assert (\c. fst(dest_const c) = `?`) in
    \tm. (let (_,b) = (check # I) (dest_comb tm) in dest_pabs b) ?
	 failwith `dest_pexists`;;

let dest_pselect =
    let check = assert (\c. fst(dest_const c) = `@`) in
    \tm. (let (_,b) = (check # I) (dest_comb tm) in dest_pabs b) ?
	 failwith `dest_pselect`;;

% ===================================================================== %
% Discriminators for paired HOL syntax.                                 %
% ===================================================================== %

let is_pabs    = can dest_pabs and
    is_pforall = can dest_pforall and
    is_pexists = can dest_pexists and
    is_pselect = can dest_pselect;;

% ===================================================================== %
% All the elements in a pair struture.                                  %
% ===================================================================== %

letrec rip_pair p = ($@ ((rip_pair # rip_pair) (dest_pair p))) ? [p];;

% ===================================================================== %
% Check if a term is a pair structure of variables.                     %
% ===================================================================== %

let is_pvar = (forall is_var) o rip_pair ;;

% ===================================================================== %
% Paired version of variant.                                            %
% ===================================================================== %

let pvariant =
    letrec uniq l =
	if null l then
	    []
	else
	    let (h.t) = l in
		h.(uniq (filter (\e. not (e = h)) t)) in
    letrec variantl avl vl = 
	if null vl then
	    []
	else
	    let (h.t) = vl in
	    let h' = (variant (avl@(filter is_var t)) h) in
		(h',h).(variantl (h'.avl) t)
    in
    \pl p.
	let avoid = (flat (map ((map (assert is_var)) o rip_pair) pl)) in
	let originals =
	    uniq (map (assert (\p. (is_var p) or (is_const p))) (rip_pair p)) in
	let sub = variantl avoid originals in
	    subst sub p;;

% ===================================================================== %
% Generates a pair structure of variable with the same structure as     %
% its parameter.                                                        %
% ===================================================================== %

letrec genlike p =
    if is_pair p then
	mk_pair ((genlike # genlike) (dest_pair p))
    else
	genvar (type_of p);;

% ===================================================================== %
% Iterated paired constructors:                                         %
%                                                                       %
%  * list_mk_pabs ([p1;...;pn],t)           --->   "\p1 ... pn.t"       %
%  * list_mk_pforall ([p1;...;pn],t)        --->   "!p1 ... pn.t"       %
%  * list_mk_pexists ([p1;...;pn],t)        --->   "?p1 ... pn.t"       %
% ===================================================================== %

let list_mk_pabs (pl, t) =
    (itlist (curry mk_pabs) pl t) ? failwith `list_mk_pabs`;;
let list_mk_pforall (pl, t) =
    (itlist (curry mk_pforall) pl t) ? failwith `list_mk_pforall`;;
let list_mk_pexists (pl, t) =
    (itlist (curry mk_pexists) pl t) ? failwith `list_mk_pexists`;;

% ===================================================================== %
% Iterated paired destructors:                                          %
%                                                                       %
%  * strip_abs "\p1 ... pn. t"           --->   [p1; ...; pn], t        %
%  * strip_forall "!p1 ... pn. t"        --->   [p1; ...; pn], t        %
%  * strip_exists "?p1 ... pn. t"        --->   [p1; ...; pn], t        %
% ===================================================================== %
letrec strip_pabs tm =
    (let (bp,body) = dest_pabs tm in
     let (bps,core) = strip_pabs body in
	(bp.bps, core))
    ? ([],tm);;

letrec strip_pforall tm =
    (let (bp,body) = dest_pforall tm in
     let (bps,core) = strip_pforall body in
	(bp.bps,core))
    ? ([],tm);;

letrec strip_pexists tm =
    (let (bp,body) = dest_pexists tm in
     let (bps,core) = strip_pexists body in
	(bp.bps,core))
    ? ([],tm);;

% ===================================================================== %
% Paired bound variable and body.                                       %
% ===================================================================== %

let bndpair tm = fst (dest_pabs tm) ? failwith `bndpair`
and pbody tm = snd (dest_pabs tm) ? failwith `pbody` ;;

% ===================================================================== %
% Occurence check for bound pairs.                                      %
% occs_in p t    true iff any of the variables in p occure free in t    %
% ===================================================================== %

let occs_in =
    letrec occs_check vl t =
	if is_const t then
	    false
	else if is_var t then
	    mem t vl
	else if is_comb t then
	    let (t1,t2) = dest_comb t in
		(occs_check vl t1) or (occs_check vl t2)
	else % is_abs %
	    let (x,b) = dest_abs t in
		occs_check (filter (\v. (not (v = x))) vl) b
    in
	\p t.
	    if is_pvar p then
		let vs = frees p in
		    occs_check vs t
	    else
		failwith `occs_in: not a pvar`;;

% ===================================================================== %
% Extra support of manipulating product types.                          %
% ===================================================================== %

let is_prod t =
    let (ty_name, l) = dest_type t in
	((ty_name = `prod`) & ((length l) = 2)) ;;

let dest_prod t =
    (let (ty_name, [ty1;ty2]) = dest_type t in
	if ty_name = `prod` then
	    (ty1,ty2)
	else
	    fail
    ) ? failwith `dest_prod`;;

let mk_prod (ty1,ty2) = mk_type (`prod`,[ty1;ty2]);;

APT Browse - Built by Thomas Orozco.