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Original Path: trunk/webwork2/lib/WeBWorK/PG/Local.pm
| 1 : | gage | 1247 | ################################################################################ |
| 2 : | sh002i | 1663 | # WeBWorK Online Homework Delivery System |
| 3 : | sh002i | 3973 | # Copyright © 2000-2006 The WeBWorK Project, http://openwebwork.sf.net/ |
| 4 : | sh002i | 4195 | # $CVSHeader: webwork2/lib/WeBWorK/PG/Local.pm,v 1.20 2006/05/21 00:50:04 gage Exp $ |
| 5 : | sh002i | 1663 | # |
| 6 : | # This program is free software; you can redistribute it and/or modify it under | ||
| 7 : | # the terms of either: (a) the GNU General Public License as published by the | ||
| 8 : | # Free Software Foundation; either version 2, or (at your option) any later | ||
| 9 : | # version, or (b) the "Artistic License" which comes with this package. | ||
| 10 : | # | ||
| 11 : | # This program is distributed in the hope that it will be useful, but WITHOUT | ||
| 12 : | # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS | ||
| 13 : | # FOR A PARTICULAR PURPOSE. See either the GNU General Public License or the | ||
| 14 : | # Artistic License for more details. | ||
| 15 : | gage | 1247 | ################################################################################ |
| 16 : | |||
| 17 : | package WeBWorK::PG::Local; | ||
| 18 : | sh002i | 1558 | use base qw(WeBWorK::PG); |
| 19 : | gage | 1247 | |
| 20 : | =head1 NAME | ||
| 21 : | |||
| 22 : | WeBWorK::PG::Local - Use the WeBWorK::PG API to invoke a local | ||
| 23 : | WeBWorK::PG::Translator object. | ||
| 24 : | |||
| 25 : | =head1 DESCRIPTION | ||
| 26 : | |||
| 27 : | WeBWorK::PG::Local encapsulates the PG translation process, making multiple | ||
| 28 : | calls to WeBWorK::PG::Translator. Much of the flexibility of the Translator is | ||
| 29 : | sh002i | 1703 | hidden, instead making choices that are appropriate for the webwork2 |
| 30 : | gage | 1247 | system |
| 31 : | |||
| 32 : | It implements the WeBWorK::PG interface and uses a local | ||
| 33 : | WeBWorK::PG::Translator to perform problem rendering. See the documentation for | ||
| 34 : | the WeBWorK::PG module for information about the API. | ||
| 35 : | |||
| 36 : | =cut | ||
| 37 : | |||
| 38 : | use strict; | ||
| 39 : | use warnings; | ||
| 40 : | gage | 3311 | use WeBWorK::Constants; |
| 41 : | gage | 1247 | use File::Path qw(rmtree); |
| 42 : | use WeBWorK::PG::Translator; | ||
| 43 : | sh002i | 1558 | use WeBWorK::Utils qw(readFile writeTimingLogEntry); |
| 44 : | gage | 1247 | |
| 45 : | sh002i | 4195 | use mod_perl; |
| 46 : | use constant MP2 => ( exists $ENV{MOD_PERL_API_VERSION} and $ENV{MOD_PERL_API_VERSION} >= 2 ); | ||
| 47 : | |||
| 48 : | sh002i | 2268 | # Problem processing will time out after this number of seconds. |
| 49 : | gage | 3311 | use constant TIMEOUT => $WeBWorK::PG::Local::TIMEOUT || 10; |
| 50 : | sh002i | 2268 | |
| 51 : | sh002i | 1558 | BEGIN { |
| 52 : | # This safe compartment is used to read the large macro files such as | ||
| 53 : | # PG.pl, PGbasicmacros.pl and PGanswermacros and cache the results so that | ||
| 54 : | # future calls have preloaded versions of these large files. This saves a | ||
| 55 : | # significant amount of time. | ||
| 56 : | gage | 1249 | $WeBWorK::PG::Local::safeCache = new Safe; |
| 57 : | } | ||
| 58 : | sh002i | 1558 | |
| 59 : | gage | 1247 | sub new { |
| 60 : | my $invocant = shift; | ||
| 61 : | gage | 3311 | local $SIG{ALRM} = \&alarm_handler; |
| 62 : | sh002i | 2268 | alarm TIMEOUT; |
| 63 : | my $result = eval { $invocant->new_helper(@_) }; | ||
| 64 : | alarm 0; | ||
| 65 : | die $@ if $@; | ||
| 66 : | return $result; | ||
| 67 : | } | ||
| 68 : | |||
| 69 : | gage | 3311 | sub alarm_handler { |
| 70 : | my $msg = "Timeout after processing this problem for ". TIMEOUT. " seconds. Check for infinite loops in problem source.\n"; | ||
| 71 : | warn $msg; | ||
| 72 : | die $msg; | ||
| 73 : | |||
| 74 : | } | ||
| 75 : | sh002i | 2268 | sub new_helper { |
| 76 : | my $invocant = shift; | ||
| 77 : | gage | 1247 | my $class = ref($invocant) || $invocant; |
| 78 : | my ( | ||
| 79 : | $ce, | ||
| 80 : | $user, | ||
| 81 : | $key, | ||
| 82 : | $set, | ||
| 83 : | $problem, | ||
| 84 : | $psvn, | ||
| 85 : | $formFields, # in CGI::Vars format | ||
| 86 : | $translationOptions, # hashref containing options for the | ||
| 87 : | # translator, such as whether to show | ||
| 88 : | sh002i | 1558 | # hints and the display mode to use |
| 89 : | gage | 1247 | ) = @_; |
| 90 : | |||
| 91 : | # write timing log entry | ||
| 92 : | gage | 2929 | # writeTimingLogEntry($ce, "WeBWorK::PG::new", |
| 93 : | # "user=".$user->user_id.",problem=".$ce->{courseName}."/".$set->set_id."/".$problem->problem_id.",mode=".$translationOptions->{displayMode}, | ||
| 94 : | # "begin"); | ||
| 95 : | gage | 1247 | |
| 96 : | # install a local warn handler to collect warnings | ||
| 97 : | my $warnings = ""; | ||
| 98 : | local $SIG{__WARN__} = sub { $warnings .= shift } | ||
| 99 : | if $ce->{pg}->{options}->{catchWarnings}; | ||
| 100 : | |||
| 101 : | # create a Translator | ||
| 102 : | gage | 1249 | #warn "PG: creating a Translator\n"; |
| 103 : | gage | 1247 | my $translator = WeBWorK::PG::Translator->new; |
| 104 : | |||
| 105 : | # set the directory hash | ||
| 106 : | #warn "PG: setting the directory hash\n"; | ||
| 107 : | $translator->rh_directories({ | ||
| 108 : | dpvc | 3224 | macrosPath => $ce->{courseDirs}->{macrosPath}, |
| 109 : | gage | 1247 | templateDirectory => $ce->{courseDirs}->{templates}, |
| 110 : | tempDirectory => $ce->{courseDirs}->{html_temp}, | ||
| 111 : | }); | ||
| 112 : | |||
| 113 : | # evaluate modules and "extra packages" | ||
| 114 : | #warn "PG: evaluating modules and \"extra packages\"\n"; | ||
| 115 : | my @modules = @{ $ce->{pg}->{modules} }; | ||
| 116 : | sh002i | 4195 | # HACK for apache2 |
| 117 : | if (MP2) { | ||
| 118 : | push @modules, ["Apache2::Log"], ["APR::Table"]; | ||
| 119 : | } else { | ||
| 120 : | push @modules, ["Apache::Log"]; | ||
| 121 : | } | ||
| 122 : | gage | 1247 | foreach my $module_packages_ref (@modules) { |
| 123 : | my ($module, @extra_packages) = @$module_packages_ref; | ||
| 124 : | # the first item is the main package | ||
| 125 : | $translator->evaluate_modules($module); | ||
| 126 : | # the remaining items are "extra" packages | ||
| 127 : | $translator->load_extra_packages(@extra_packages); | ||
| 128 : | } | ||
| 129 : | |||
| 130 : | # set the environment (from defineProblemEnvir) | ||
| 131 : | #warn "PG: setting the environment (from defineProblemEnvir)\n"; | ||
| 132 : | sh002i | 1558 | my $envir = $class->defineProblemEnvir( |
| 133 : | gage | 1247 | $ce, |
| 134 : | $user, | ||
| 135 : | $key, | ||
| 136 : | $set, | ||
| 137 : | $problem, | ||
| 138 : | $psvn, | ||
| 139 : | $formFields, | ||
| 140 : | $translationOptions, | ||
| 141 : | ); | ||
| 142 : | $translator->environment($envir); | ||
| 143 : | |||
| 144 : | # initialize the Translator | ||
| 145 : | #warn "PG: initializing the Translator\n"; | ||
| 146 : | $translator->initialize(); | ||
| 147 : | sh002i | 1558 | |
| 148 : | # Preload the macros files which are used routinely: PG.pl, | ||
| 149 : | # dangerousMacros.pl, IO.pl, PGbasicmacros.pl, and PGanswermacros.pl | ||
| 150 : | # (Preloading the last two files safes a significant amount of time.) | ||
| 151 : | # | ||
| 152 : | # IO.pl, PG.pl, and dangerousMacros.pl are loaded using | ||
| 153 : | # unrestricted_load This is hard wired into the | ||
| 154 : | # Translator::pre_load_macro_files subroutine. I'd like to change this | ||
| 155 : | # at some point to have the same sort of interface to global.conf that | ||
| 156 : | # the module loading does -- have a list of macros to load | ||
| 157 : | # unrestrictedly. | ||
| 158 : | # | ||
| 159 : | # This has been replaced by the pre_load_macro_files subroutine. It | ||
| 160 : | # loads AND caches the files. While PG.pl and dangerousMacros are not | ||
| 161 : | # large, they are referred to by PGbasicmacros and PGanswermacros. | ||
| 162 : | # Because these are loaded into the cached name space (e.g. | ||
| 163 : | # Safe::Root1::) all calls to, say NEW_ANSWER_NAME are actually calls | ||
| 164 : | # to Safe::Root1::NEW_ANSWER_NAME. It is useful to have these names | ||
| 165 : | # inside the Safe::Root1: cached safe compartment. (NEW_ANSWER_NAME | ||
| 166 : | # and all other subroutine names are also automatically exported into | ||
| 167 : | # the current safe compartment Safe::Rootx:: | ||
| 168 : | # | ||
| 169 : | # The headers of both PGbasicmacros and PGanswermacros has code that | ||
| 170 : | # insures that the constants used are imported into the current safe | ||
| 171 : | # compartment. This involves evaluating references to, say | ||
| 172 : | # $main::displayMode, at runtime to insure that main refers to | ||
| 173 : | # Safe::Rootx:: and NOT to Safe::Root1::, which is the value of main:: | ||
| 174 : | # at compile time. | ||
| 175 : | # | ||
| 176 : | # TO ENABLE CACHEING UNCOMMENT THE FOLLOWING: | ||
| 177 : | eval{$translator->pre_load_macro_files( | ||
| 178 : | $WeBWorK::PG::Local::safeCache, | ||
| 179 : | $ce->{pg}->{directories}->{macros}, | ||
| 180 : | 'PG.pl', 'dangerousMacros.pl','IO.pl','PGbasicmacros.pl','PGanswermacros.pl' | ||
| 181 : | )}; | ||
| 182 : | warn "Error while preloading macro files: $@" if $@; | ||
| 183 : | gage | 1249 | |
| 184 : | sh002i | 1558 | # STANDARD LOADING CODE: for cached script files, this merely |
| 185 : | # initializes the constants. | ||
| 186 : | foreach (qw(PG.pl dangerousMacros.pl IO.pl)) { | ||
| 187 : | gage | 1247 | my $macroPath = $ce->{pg}->{directories}->{macros} . "/$_"; |
| 188 : | my $err = $translator->unrestricted_load($macroPath); | ||
| 189 : | sh002i | 1558 | warn "Error while loading $macroPath: $err" if $err; |
| 190 : | gage | 1247 | } |
| 191 : | sh002i | 1558 | |
| 192 : | gage | 1247 | # set the opcode mask (using default values) |
| 193 : | #warn "PG: setting the opcode mask (using default values)\n"; | ||
| 194 : | $translator->set_mask(); | ||
| 195 : | |||
| 196 : | # store the problem source | ||
| 197 : | #warn "PG: storing the problem source\n"; | ||
| 198 : | gage | 3073 | my $source =''; |
| 199 : | my $sourceFilePath = ''; | ||
| 200 : | my $readErrors = undef; | ||
| 201 : | if (ref($translationOptions->{r_source}) ) { | ||
| 202 : | # the source for the problem is already given to us as a reference to a string | ||
| 203 : | $source = ${$translationOptions->{r_source}}; | ||
| 204 : | } else { | ||
| 205 : | # the source isn't given to us so we need to read it | ||
| 206 : | # from a file defined by the problem | ||
| 207 : | |||
| 208 : | # we grab the sourceFilePath from the problem | ||
| 209 : | $sourceFilePath = $problem->source_file; | ||
| 210 : | |||
| 211 : | # the path to the source file is usually given relative to the | ||
| 212 : | # the templates directory. Unless the path starts with / assume | ||
| 213 : | # that it is relative to the templates directory | ||
| 214 : | |||
| 215 : | $sourceFilePath = $ce->{courseDirs}->{templates}."/" | ||
| 216 : | .$sourceFilePath unless ($sourceFilePath =~ /^\//); | ||
| 217 : | #now grab the source | ||
| 218 : | eval {$source = readFile($sourceFilePath) }; | ||
| 219 : | $readErrors = $@ if $@; | ||
| 220 : | } | ||
| 221 : | # put the source into the translator object | ||
| 222 : | eval { $translator->source_string( $source ) } unless $readErrors; | ||
| 223 : | $readErrors .="\n $@ " if $@; | ||
| 224 : | if ($readErrors) { | ||
| 225 : | gage | 1247 | # well, we couldn't get the problem source, for some reason. |
| 226 : | return bless { | ||
| 227 : | translator => $translator, | ||
| 228 : | gage | 1249 | head_text => "", |
| 229 : | gage | 1247 | body_text => <<EOF, |
| 230 : | gage | 3073 | WeBWorK::Utils::readFile($sourceFilePath) says: |
| 231 : | gage | 1247 | $@ |
| 232 : | EOF | ||
| 233 : | answers => {}, | ||
| 234 : | result => {}, | ||
| 235 : | state => {}, | ||
| 236 : | errors => "Failed to read the problem source file.", | ||
| 237 : | warnings => $warnings, | ||
| 238 : | flags => {error_flag => 1}, | ||
| 239 : | }, $class; | ||
| 240 : | } | ||
| 241 : | |||
| 242 : | sh002i | 1537 | # install a safety filter |
| 243 : | gage | 1247 | #warn "PG: installing a safety filter\n"; |
| 244 : | sh002i | 1537 | #$translator->rf_safety_filter(\&oldSafetyFilter); |
| 245 : | gage | 1563 | $translator->rf_safety_filter(\&WeBWorK::PG::nullSafetyFilter); |
| 246 : | gage | 1247 | |
| 247 : | # write timing log entry -- the translator is now all set up | ||
| 248 : | gage | 2929 | # writeTimingLogEntry($ce, "WeBWorK::PG::new", |
| 249 : | # "initialized", | ||
| 250 : | # "intermediate"); | ||
| 251 : | gage | 1247 | |
| 252 : | # translate the PG source into text | ||
| 253 : | #warn "PG: translating the PG source into text\n"; | ||
| 254 : | $translator->translate(); | ||
| 255 : | |||
| 256 : | # after we're done translating, we may have to clean up after the | ||
| 257 : | # translator: | ||
| 258 : | |||
| 259 : | # for example, HTML_img mode uses a tempdir for dvipng's temp files.\ | ||
| 260 : | # We have to remove it. | ||
| 261 : | if ($envir->{dvipngTempDir}) { | ||
| 262 : | rmtree($envir->{dvipngTempDir}, 0, 0); | ||
| 263 : | } | ||
| 264 : | |||
| 265 : | # HTML_dpng, on the other hand, uses an ImageGenerator. We have to | ||
| 266 : | # render the queued equations. | ||
| 267 : | jj | 2418 | my $body_text_ref = $translator->r_text; |
| 268 : | gage | 1247 | if ($envir->{imagegen}) { |
| 269 : | my $sourceFile = $ce->{courseDirs}->{templates} . "/" . $problem->source_file; | ||
| 270 : | my %mtimeOption = -e $sourceFile | ||
| 271 : | ? (mtime => (stat $sourceFile)[9]) | ||
| 272 : | : (); | ||
| 273 : | |||
| 274 : | $envir->{imagegen}->render( | ||
| 275 : | refresh => $translationOptions->{refreshMath2img}, | ||
| 276 : | %mtimeOption, | ||
| 277 : | jj | 2418 | body_text => $body_text_ref, |
| 278 : | gage | 1247 | ); |
| 279 : | } | ||
| 280 : | |||
| 281 : | my ($result, $state); # we'll need these on the other side of the if block! | ||
| 282 : | if ($translationOptions->{processAnswers}) { | ||
| 283 : | |||
| 284 : | # process student answers | ||
| 285 : | #warn "PG: processing student answers\n"; | ||
| 286 : | $translator->process_answers($formFields); | ||
| 287 : | |||
| 288 : | # retrieve the problem state and give it to the translator | ||
| 289 : | #warn "PG: retrieving the problem state and giving it to the translator\n"; | ||
| 290 : | $translator->rh_problem_state({ | ||
| 291 : | recorded_score => $problem->status, | ||
| 292 : | num_of_correct_ans => $problem->num_correct, | ||
| 293 : | num_of_incorrect_ans => $problem->num_incorrect, | ||
| 294 : | }); | ||
| 295 : | |||
| 296 : | # determine an entry order -- the ANSWER_ENTRY_ORDER flag is built by | ||
| 297 : | # the PG macro package (PG.pl) | ||
| 298 : | #warn "PG: determining an entry order\n"; | ||
| 299 : | my @answerOrder = | ||
| 300 : | $translator->rh_flags->{ANSWER_ENTRY_ORDER} | ||
| 301 : | ? @{ $translator->rh_flags->{ANSWER_ENTRY_ORDER} } | ||
| 302 : | : keys %{ $translator->rh_evaluated_answers }; | ||
| 303 : | |||
| 304 : | # install a grader -- use the one specified in the problem, | ||
| 305 : | # or fall back on the default from the course environment. | ||
| 306 : | # (two magic strings are accepted, to avoid having to | ||
| 307 : | # reference code when it would be difficult.) | ||
| 308 : | #warn "PG: installing a grader\n"; | ||
| 309 : | my $grader = $translator->rh_flags->{PROBLEM_GRADER_TO_USE} | ||
| 310 : | || $ce->{pg}->{options}->{grader}; | ||
| 311 : | $grader = $translator->rf_std_problem_grader | ||
| 312 : | if $grader eq "std_problem_grader"; | ||
| 313 : | $grader = $translator->rf_avg_problem_grader | ||
| 314 : | if $grader eq "avg_problem_grader"; | ||
| 315 : | die "Problem grader $grader is not a CODE reference." | ||
| 316 : | unless ref $grader eq "CODE"; | ||
| 317 : | $translator->rf_problem_grader($grader); | ||
| 318 : | |||
| 319 : | # grade the problem | ||
| 320 : | #warn "PG: grading the problem\n"; | ||
| 321 : | ($result, $state) = $translator->grade_problem( | ||
| 322 : | answers_submitted => $translationOptions->{processAnswers}, | ||
| 323 : | ANSWER_ENTRY_ORDER => \@answerOrder, | ||
| 324 : | gage | 4089 | %{$formFields}, #FIXME? this is used by sequentialGrader is there a better way? |
| 325 : | gage | 1247 | ); |
| 326 : | |||
| 327 : | } | ||
| 328 : | |||
| 329 : | # write timing log entry | ||
| 330 : | gage | 2929 | # writeTimingLogEntry($ce, "WeBWorK::PG::new", "", "end"); |
| 331 : | gage | 1247 | |
| 332 : | # return an object which contains the translator and the results of | ||
| 333 : | # the translation process. this is DIFFERENT from the "format expected | ||
| 334 : | # by Webwork.pm (and I believe processProblem8, but check.)" | ||
| 335 : | return bless { | ||
| 336 : | translator => $translator, | ||
| 337 : | head_text => ${ $translator->r_header }, | ||
| 338 : | jj | 2418 | body_text => ${ $body_text_ref }, |
| 339 : | gage | 1247 | answers => $translator->rh_evaluated_answers, |
| 340 : | result => $result, | ||
| 341 : | state => $state, | ||
| 342 : | errors => $translator->errors, | ||
| 343 : | warnings => $warnings, | ||
| 344 : | flags => $translator->rh_flags, | ||
| 345 : | }, $class; | ||
| 346 : | } | ||
| 347 : | |||
| 348 : | 1; | ||
| 349 : | |||
| 350 : | __END__ | ||
| 351 : | |||
| 352 : | =head1 OPERATION | ||
| 353 : | |||
| 354 : | sh002i | 1558 | WeBWorK::PG::Local goes through the following operations when constructed: |
| 355 : | gage | 1247 | |
| 356 : | =over | ||
| 357 : | |||
| 358 : | =item Create a translator | ||
| 359 : | |||
| 360 : | Instantiate a WeBWorK::PG::Translator object. | ||
| 361 : | |||
| 362 : | =item Set the directory hash | ||
| 363 : | |||
| 364 : | Set the translator's directory hash (courseScripts, macros, templates, and temp | ||
| 365 : | directories) from the course environment. | ||
| 366 : | |||
| 367 : | =item Evaluate PG modules | ||
| 368 : | |||
| 369 : | Using the module list from the course environment (pg->modules), perform a | ||
| 370 : | "use"-like operation to evaluate modules at runtime. | ||
| 371 : | |||
| 372 : | =item Set the problem environment | ||
| 373 : | |||
| 374 : | sh002i | 1558 | Use data from the user, set, and problem, as well as the course |
| 375 : | environemnt and translation options, to set the problem environment. The | ||
| 376 : | default subroutine, &WeBWorK::PG::defineProblemEnvir, is used. | ||
| 377 : | gage | 1247 | |
| 378 : | =item Initialize the translator | ||
| 379 : | |||
| 380 : | Call &WeBWorK::PG::Translator::initialize. What more do you want? | ||
| 381 : | |||
| 382 : | sh002i | 1558 | =item Load IO.pl, PG.pl and dangerousMacros.pl |
| 383 : | gage | 1247 | |
| 384 : | These macros must be loaded without opcode masking, so they are loaded here. | ||
| 385 : | |||
| 386 : | =item Set the opcode mask | ||
| 387 : | |||
| 388 : | Set the opcode mask to the default specified by WeBWorK::PG::Translator. | ||
| 389 : | |||
| 390 : | =item Load the problem source | ||
| 391 : | |||
| 392 : | Give the problem source to the translator. | ||
| 393 : | |||
| 394 : | =item Install a safety filter | ||
| 395 : | |||
| 396 : | The safety filter is used to preprocess student input before evaluation. The | ||
| 397 : | default safety filter, &WeBWorK::PG::safetyFilter, is used. | ||
| 398 : | |||
| 399 : | =item Translate the problem source | ||
| 400 : | |||
| 401 : | Call &WeBWorK::PG::Translator::translate to render the problem source into the | ||
| 402 : | format given by the display mode. | ||
| 403 : | |||
| 404 : | =item Process student answers | ||
| 405 : | |||
| 406 : | Use form field inputs to evaluate student answers. | ||
| 407 : | |||
| 408 : | =item Load the problem state | ||
| 409 : | |||
| 410 : | Use values from the database to initialize the problem state, so that the | ||
| 411 : | grader will have a point of reference. | ||
| 412 : | |||
| 413 : | =item Determine an entry order | ||
| 414 : | |||
| 415 : | Use the ANSWER_ENTRY_ORDER flag to determine the order of answers in the | ||
| 416 : | problem. This is important for problems with dependancies among parts. | ||
| 417 : | |||
| 418 : | =item Install a grader | ||
| 419 : | |||
| 420 : | Use the PROBLEM_GRADER_TO_USE flag, or a default from the course environment, | ||
| 421 : | to install a grader. | ||
| 422 : | |||
| 423 : | =item Grade the problem | ||
| 424 : | |||
| 425 : | Use the selected grader to grade the problem. | ||
| 426 : | |||
| 427 : | =back | ||
| 428 : | |||
| 429 : | =head1 AUTHOR | ||
| 430 : | |||
| 431 : | Written by Sam Hathaway, sh002i (at) math.rochester.edu. | ||
| 432 : | |||
| 433 : | =cut |
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