Leonardo de Moura
33e562a7ce
fix(frontends/lean/structure_cmd): effect of "include" command in the structure command
...
closes #438
2015-02-19 22:44:51 -08:00
Leonardo de Moura
421a30d75c
feat(library): export [reducible] annotations from function namespace to top-level
...
see issue #433
2015-02-16 18:52:41 -08:00
Leonardo de Moura
7fc216183e
feat(library/tactic): produce better error message when a tactic fails
...
closes #348
2015-02-16 18:42:15 -08:00
Leonardo de Moura
461c02d790
fix(tests/lean/hott/433): remove bogus comment, and use rewrite tactic
...
Fix an issue raised by Floris.
See discussion at
https://github.com/leanprover/lean/issues/433
2015-02-16 15:45:31 -08:00
Leonardo de Moura
4248ad644d
fix(frontends/lean): priority expressions parser
2015-02-14 12:26:06 -08:00
Leonardo de Moura
5cbdd77ad0
feat(library/tactic/rewrite_tactic): improve matcher in rewrite_tactic
...
closes #433
2015-02-13 12:40:55 -08:00
Leonardo de Moura
8ffadce4ab
feat(frontends/lean): add "premise" and "premises" command
...
It is just an alternative notation for "variable" and "variables"
closes #429
2015-02-11 18:46:03 -08:00
Leonardo de Moura
04e92e1e96
feat(frontends/lean/parser): reject explicit universe levels in variables and parameters
...
This modification was motivated by issue #427
2015-02-11 16:25:06 -08:00
Leonardo de Moura
a35cce38b3
feat(frontends/lean): new semantics for "protected" declarations
...
closes #426
2015-02-11 14:09:25 -08:00
Leonardo de Moura
eceed03044
feat(frontends/lean): add "except" notation for "open" command, allow multiple metaclasses to be opened in a single "open" command
2015-02-11 11:02:59 -08:00
Leonardo de Moura
1832fb6f54
feat(*): uniform metaclass names, metaclass validation at 'open' command
2015-02-11 10:35:04 -08:00
Leonardo de Moura
9d1cd073c5
feat(frontends/lean): add 'print metaclasses' command
2015-02-11 10:13:20 -08:00
Leonardo de Moura
60fca7575c
fix(frontends/lean/pp): bugs when pretty printing abbreviations
2015-02-10 19:06:09 -08:00
Leonardo de Moura
f9832fb89f
test(tests/lean/abbrev1): add test for abbreviation command
2015-02-10 18:28:48 -08:00
Leonardo de Moura
014271da8b
feat(frontends/lean): better error messages for ill-terminated declarations
2015-02-10 14:38:00 -08:00
Leonardo de Moura
f018fdabb9
refactor(library/kernel_bindings): remove unnecessary procedure
2015-02-07 18:57:46 -08:00
Leonardo de Moura
c04c0e8381
refactor(*): remove transparent_scope hack, replace [strict] with [all-transparent] annotation
2015-02-07 15:19:41 -08:00
Leonardo de Moura
2126b8ec9a
feat(library/tactic/apply_tactic): perform class-instance resolution in the apply tactic
...
closes #360
2015-02-06 16:14:03 -08:00
Leonardo de Moura
1e8a975daa
feat(frontends/lean): extend parser: rewrite "fold" step
2015-02-06 15:22:34 -08:00
Leonardo de Moura
04f8278c90
test(tests/lean/run): add rewrite tactic test
2015-02-06 14:14:42 -08:00
Leonardo de Moura
5b25da8c43
feat(frontends/lean): add esimp tactic based on rewrite tactic
...
closes #358
2015-02-06 14:13:32 -08:00
Leonardo de Moura
b4139627e5
feat(library/tactic/rewrite_tactic): add option to prevent any kind of constant unfolding when perfoming pattern matching in the rewrite tactic
2015-02-06 13:27:33 -08:00
Leonardo de Moura
78bde6c9e6
test(tests/lean/run): add more rewrite tactic tests
2015-02-06 12:57:42 -08:00
Leonardo de Moura
2e626b29fb
feat(library/tactic/rewrite_tactic): allow many constants to be provided in a single rewrite unfold step
2015-02-06 11:03:36 -08:00
Leonardo de Moura
56a46ae61e
feat(frontends/lean/parse_tactic_location): make rewrite notation more uniform
2015-02-06 10:31:50 -08:00
Leonardo de Moura
e17ba27596
fix(library/tactic/rewrite_tactic): adjust the behavior of class resolution in rewriter
...
The solution is not very satisfactory. I should investigate it more.
2015-02-05 19:08:47 -08:00
Leonardo de Moura
e097977bac
test(tests/lean/run): add more rewrite tactic tests
2015-02-05 14:09:07 -08:00
Leonardo de Moura
ffe0d1186e
feat(library/tactic/rewrite_tactic): add "reduce_to" step at rewrite tactic
2015-02-05 13:59:55 -08:00
Leonardo de Moura
116c65bff5
feat(library/tactic/rewrite_tactic): add reduction step to rewrite tactic
2015-02-05 13:42:50 -08:00
Leonardo de Moura
808521223b
feat(library/tactic/rewrite_tactic): support constant unfolding in rewrite tactic
2015-02-05 12:58:30 -08:00
Leonardo de Moura
1b73764ad3
fix(tests/lean/run/elim2): adjust test to reflect recent changes
2015-02-05 10:54:00 -08:00
Leonardo de Moura
d6958be7e7
fix(library/tactic/location): replace cache must not be used when only a subset of all occurrences should be replaced at replace_occurrences
2015-02-05 10:50:40 -08:00
Leonardo de Moura
dfad24e3f5
feat(frontends/lean): polish rewrite tactic notation
2015-02-05 10:15:58 -08:00
Leonardo de Moura
0abfa30ead
fix(library/tactic/rewrite_tactic): elaboration bug in the rewrite tactic steps/elements
2015-02-05 10:01:18 -08:00
Leonardo de Moura
15efadfbdc
feat(frontends/lean/parse_rewrite_tactic): cleanup rewrite tactic notation
...
Make a rewrite command sequence explicit.
2015-02-04 20:16:24 -08:00
Leonardo de Moura
14c72e82f6
feat(library/tactic/rewrite_tactic): add support for rewriting hypotheses
2015-02-04 20:04:19 -08:00
Leonardo de Moura
90eb5c8ca5
test(tests/lean/hott): add test for rewriter in the HoTT version
2015-02-04 19:33:08 -08:00
Leonardo de Moura
61a029d9df
fix(tests/lean/rewrite_loop): notation
2015-02-04 19:21:26 -08:00
Leonardo de Moura
d0171ffe7a
test(tests/lean/run): add more rewrite tactic examples
2015-02-04 19:19:46 -08:00
Leonardo de Moura
89fde9d829
feat(library/tactic/rewrite_tactic): add maximum number of iterations threshold to rewrite tactic
...
The idea is to avoid nontermination.
2015-02-04 16:13:15 -08:00
Leonardo de Moura
0c8eaa38c8
test(tests/lean/run): add basic rewriter test
2015-02-04 15:30:18 -08:00
Leonardo de Moura
2a6ccb252e
test(tests/lean/extra): add regression tests for issue #422
2015-02-04 10:55:03 -08:00
Leonardo de Moura
f79f43c702
refactor(library/match): use "special" meta-variables instead of free variables to represent placholders in the higher-order matcher
2015-02-03 15:15:04 -08:00
Leonardo de Moura
10357f3f53
fix(tests/lean/nonexhaustive): remove line "warning: imported file uses 'sorry'" from test produced output
2015-02-01 21:25:52 -08:00
Leonardo de Moura
36cfb7fac0
test(tests/lean/bad_set_option): add tests for bad 'set_option' command
2015-02-01 20:20:35 -08:00
Leonardo de Moura
9d1e312c12
test(tests/lean/extra): add extra tests for 'print' command
2015-02-01 20:20:26 -08:00
Leonardo de Moura
ed85ac254a
test(tests/lean): add more tests for error messages
2015-02-01 20:04:22 -08:00
Leonardo de Moura
3f37c0e739
test(tests/lean/run): add 'export' command test
2015-02-01 19:57:26 -08:00
Leonardo de Moura
7d9d89bae6
test(tests/lean/extra): add test for saving recursive equation pre-terms
2015-02-01 19:49:14 -08:00
Leonardo de Moura
2403d555ee
test(tests/lean/bad_eqns): add tests for definition package error messages
2015-02-01 19:36:06 -08:00
Leonardo de Moura
6cd4972a84
fix(tests/lean): adjust tests to reflect changes in the standard library
2015-02-01 11:36:38 -08:00
Leonardo de Moura
15716c1471
feat(frontends/lean/calc_proof_elaborator): reject proofs with metavariables in the calc-assistant
2015-02-01 11:11:27 -08:00
Leonardo de Moura
143143e94c
fix(library/tactic/inversion_tactic): missing normalization step in the inversion_tactic
2015-02-01 10:38:30 -08:00
Leonardo de Moura
d52af105d7
feat(frontends/lean/decl_cmds): allow many constants to be set in the same attribute command
2015-01-31 23:55:14 -08:00
Leonardo de Moura
ea9a9d63d1
test(tests/lean): add tests for structure command error messages
2015-01-30 09:52:42 -08:00
Leonardo de Moura
7c59c959db
fix(tests/lean/interactive): do not compare output of trace using non-deterministic commands such as "WAIT ms"
2015-01-30 09:52:42 -08:00
Leonardo de Moura
e75828b756
test(tests/lean/interactive): add tests for options structure.eta_thm and structure.proj_mk_thm
2015-01-29 16:52:23 -08:00
Leonardo de Moura
e9d8a960d9
test(tests/lean/interactive): add test for proof_state info
2015-01-29 16:44:10 -08:00
Leonardo de Moura
c74da8bea2
test(tests/lean/interactive): add tests for coercion and overload info
2015-01-29 16:39:27 -08:00
Leonardo de Moura
f04e462bf3
test(tests/lean/interactive): add more tests for lean server
2015-01-29 16:30:07 -08:00
Leonardo de Moura
e9e1f86b7f
fix(library/app_builder): many bugs, add use_cache option, add tests
2015-01-29 15:30:31 -08:00
Leonardo de Moura
5bb2a41c64
feat(library/reducible): expose Lua API for reducible hints
2015-01-29 10:37:15 -08:00
Leonardo de Moura
e4b5e07498
fix(frontends/lean/elaborator): apply substitution before compiling pre-tactics into tactics
...
closes #415
2015-01-28 13:32:56 -08:00
Leonardo de Moura
94519b48b1
fix(tests/lean): adjust tests to reflect changes in the standard library
2015-01-27 11:37:17 -08:00
Leonardo de Moura
ad4c7c20f9
fix(kernel/inductive/inductive): fix assertion violation when K is applied to type incorrect term
2015-01-27 11:22:14 -08:00
Leonardo de Moura
e2c41fca75
feat(frontends/lean): modify syntax for local notation
...
The idea is to make it uniform with the syntax for defining local
attributes.
2015-01-26 11:51:17 -08:00
Leonardo de Moura
b4d6f6e3ed
feat(frontends/lean): 'attribute' command is persistent by default
2015-01-26 11:51:17 -08:00
Leonardo de Moura
a1eeb0a6a1
fix(library/print): typo in is_used_name
...
closes #408
2015-01-25 08:58:08 -08:00
Leonardo de Moura
4f2e0c6d7f
refactor(frontends/lean): add 'attribute' command
...
The new command provides a uniform way to set declaration attributes.
It replaces the commands: class, instance, coercion, multiple_instances,
reducible, irreducible
2015-01-24 20:23:21 -08:00
Leonardo de Moura
b5c4e603db
feat(frontends/lean): allow parameters to be used in sections
...
Restriction:
- coercions and notations cannot be defined in parametric sections
closes #401
2015-01-23 17:42:19 -08:00
Leonardo de Moura
42b5b1e679
test(tests/lean): add new test for scoping rules
2015-01-22 11:41:19 -08:00
Leonardo de Moura
880faf89e0
feat(frontends/lean/structure_cmd): add implicit_infer_kind annotation to structure command
...
closes #354
2015-01-21 18:12:29 -08:00
Leonardo de Moura
12674114a4
feat(shell): set default behavior to "trusted"
...
closes #402
2015-01-21 16:25:09 -08:00
Leonardo de Moura
f2e878dbe7
fix(tests/lua/res1): adjust test to recent modifications
2015-01-20 16:26:41 -08:00
Leonardo de Moura
260795f981
fix(frontends/lean/structure_cmd): collect universe levels that only occur in structure parameters
...
fixes #395
2015-01-19 22:18:09 -08:00
Leonardo de Moura
002050fa97
feat(frontends/lean): increase binding power of ! and @
...
Remark: I did not add the constant "app".
Reason: It would break the standard library in many places.
Moreover, the current "max" is not just the binding power of
application, but also the binding power of identifiers, (, [, ...
It would be weird to call it "app"
closes #388
2015-01-19 18:40:33 -08:00
Leonardo de Moura
6fd0d452d3
test(tests/lean/run): adjust tests to reflect recent changes
2015-01-19 18:00:14 -08:00
Leonardo de Moura
edcc92d9c7
feat(frontends/lean): remove 'using' from structure instance command
2015-01-17 09:38:10 -08:00
Leonardo de Moura
fed96c9e0b
test(tests/lean/run): add structure instance example
2015-01-17 09:27:15 -08:00
Leonardo de Moura
f9d7480f5c
feat(frontends/lean): notation for creating structure instances
2015-01-16 17:14:30 -08:00
Leonardo de Moura
bfd679d52d
feat(frontends/lean/structure_cmd): allow user to reference parent structures when defining new fields
...
See new test for an example.
closes #371
2015-01-16 13:04:48 -08:00
Leonardo de Moura
6c07ca5d41
perf(library/print): improve is_used_name
2015-01-15 19:01:13 -08:00
Leonardo de Moura
91366c989d
test(tests/lean/run/finbug): add problematic definition test
2015-01-13 18:49:37 -08:00
Leonardo de Moura
37e852ba61
feat(frontends/lean/elaborator): improve error message for metavariable in inaccessible position on equation lhs
2015-01-13 14:38:25 -08:00
Leonardo de Moura
e5a8c67d22
fix(library/definitional/equations): assertion violation
2015-01-13 11:57:14 -08:00
Leonardo de Moura
1fbfe59a9a
feat(library/tactic/goal): when listing context/goal variables, collect vars of same type in one line
...
closes #391
2015-01-13 11:14:44 -08:00
Leonardo de Moura
75d7e4ab9e
feat(frontends/lean): add 'end' token to match expressions
2015-01-10 12:35:29 -08:00
Leonardo de Moura
d6eccd7c18
test(tests/lean/run): add match test
2015-01-10 10:43:24 -08:00
Leonardo de Moura
b172229a72
feat(frontends/lean): add 'match' expressions
...
We reuse the equations infrastructure to compile them.
2015-01-10 10:11:13 -08:00
Leonardo de Moura
6df9ffe5f6
fix(frontends/lean/elaborator): solve placeholders before invoking equantions compiler
2015-01-10 09:18:27 -08:00
Leonardo de Moura
a3bc1b0cd5
fix(library/definitional/equations): add more equation validation to avoid obscure error message
2015-01-09 18:52:21 -08:00
Leonardo de Moura
2e4a2451e6
refactor(library/reducible): simplify reducible/irreducible semantics
2015-01-08 18:52:18 -08:00
Leonardo de Moura
0ffb7c080f
fix(tests/lean/run/inv_bug2): adjust test to reflect changes at data.vector
2015-01-08 12:11:52 -08:00
Leonardo de Moura
698754b2bb
feat(library/definitional/equations): display elaborated equation lhs's when there are missing cases
2015-01-08 12:00:47 -08:00
Leonardo de Moura
4e49e73585
refactor(library/init/logic): add inhabited related functions, rename inhabited.default to default
2015-01-07 18:45:58 -08:00
Leonardo de Moura
1fab144aa7
refactor(library/init/nat): rename constants
...
closes #387
2015-01-07 18:26:51 -08:00
Jeremy Avigad
50f03c5a09
refactor(library/data/nat/order): make nat order an instance of linear_ordered_semigroup, rename various theorems
2015-01-07 18:18:28 -08:00
Leonardo de Moura
a3a6697f44
feat(library/definitional/equations): mutually recursive functions for mutually recursive datatypes
2015-01-06 14:07:17 -08:00
Leonardo de Moura
fb1cb3c623
test(tests/lean/run): define tree_list length function using recursive equations
...
tree_list is part of a mutually inductive datatype.
2015-01-06 11:57:34 -08:00
Leonardo de Moura
559ee3e3e1
fix(util/buffer): bug in expand method
...
fixes #385
2015-01-06 11:42:40 -08:00
Leonardo de Moura
6451cad38d
test(tests/lean/run): define list head using recursive equations
2015-01-05 19:50:34 -08:00
Leonardo de Moura
3325d791de
fix(library/definitional/equations): bug in recursive application elimination
2015-01-05 17:17:14 -08:00
Leonardo de Moura
cbae6a2ca0
test(tests/lean/run): define list filter function using recursive equations
2015-01-05 17:05:01 -08:00
Leonardo de Moura
a24a7f7fa1
test(tests/lean/run) define vector last and unzip functions using recursive equations
2015-01-05 17:04:55 -08:00
Leonardo de Moura
eedc31f7e9
fix(library/definitional/equations): bug in "complete" transition
2015-01-05 16:27:29 -08:00
Leonardo de Moura
3889b60152
feat(library/definitional/equations): allow inductive datatype parameters in recursive equations
2015-01-05 15:56:28 -08:00
Leonardo de Moura
d8f3bcec67
feat(library/init/logic): add 'arbitrary'
...
It is identical to default, but it is opaque.
That is, when we use 'arbitrary A', we cannot rely on the particular
value selected.
2015-01-05 13:27:09 -08:00
Leonardo de Moura
0d84943d52
test(tests/lean/run): show that nat has decidable equality using recursive equations
2015-01-05 12:41:18 -08:00
Leonardo de Moura
fd332e411d
test(tests/lean/run): add more overlapping patterns examples
2015-01-05 12:25:14 -08:00
Leonardo de Moura
b46c377aa2
feat(library/definitional/equations): add "complete" transition for overlapping patterns
2015-01-05 11:49:27 -08:00
Leonardo de Moura
fdef3e5407
feat(library/definitional/equations): add support for reflexive datatypes in the definitional package
2015-01-05 11:13:35 -08:00
Leonardo de Moura
5e228d92d2
fix(library/definitional/equations): missing case
2015-01-04 20:49:53 -08:00
Leonardo de Moura
f07475667b
test(tests/lean/run): define vector map using recursive equations
2015-01-04 19:56:50 -08:00
Leonardo de Moura
7ff03e2846
test(tests/lean/run): define vector diagonal using recursive equations
2015-01-04 17:58:35 -08:00
Leonardo de Moura
7488378445
test(tests/lean/run): define list append using recursive equations
2015-01-04 17:58:24 -08:00
Leonardo de Moura
7fca862fc3
test(tests/lean/run): define fibonacci using recursive equations
2015-01-04 17:47:18 -08:00
Leonardo de Moura
faf78ce3e6
feat(library/definitional/equations): brec_on compilation
2015-01-04 17:45:13 -08:00
Leonardo de Moura
5bf8141af2
test(tests/lean/hott): add test to demonstrate limitations of the current compilation procedure
2015-01-02 23:18:35 -08:00
Leonardo de Moura
92b6c06a21
test(tests/lean/run): add basic pattern matching compilation test
2015-01-02 22:22:20 -08:00
Leonardo de Moura
c66826787a
test(tests/lean/run): add basic pattern matching compilation test
2015-01-02 22:07:31 -08:00
Leonardo de Moura
7f7d318b22
feat(library/definitional/equations): add dependent pattern matching compilation
2015-01-02 22:06:40 -08:00
Jeremy Avigad
1eea75b6fc
fix(library/data/nat/div,tests/lean/run/ppbeta): make decidable for dvd transparent, name change in ppbeta
2014-12-26 16:44:43 -05:00
Jeremy Avigad
25394dddb7
refactor(library): change mul.left_id to mul_one, and similarly for mul.right_id, add.left_id, add.right_id
2014-12-23 21:14:36 -05:00
Jeremy Avigad
486bc321ff
refactor(library/data/nat): rename theorems
2014-12-23 21:14:35 -05:00
Leonardo de Moura
2be83fbff7
test(tests/lean): remove data.nat dependency
2014-12-23 17:42:56 -08:00
Leonardo de Moura
264c88d332
test(tests/lean/hott): add tele_eq example using HoTT library
2014-12-22 09:43:16 -08:00
Leonardo de Moura
1d79cb9c07
fix(library/tactic/inversion_tactic): fix bug in 'cases' tactic for HoTT library
2014-12-22 09:40:15 -08:00
Leonardo de Moura
d2958044fd
feat(frontends/lean): add multiple_instances command
...
After this commit, Lean "cuts" the search after the first instance is
computed. To obtain the previous behavior, we must use the new command
multiple_instances <class-name>
closes #370
2014-12-21 17:28:44 -08:00
Leonardo de Moura
5efadb09cc
feat(library/tactic/inversion_tactic): improve 'cases' tactic for HoTT library
...
This commit adds support for hypotheses (h : C As idxs) where the indices idxs
are just local constants. Before this commit the indices idxs had to be hsets.
Now, they can be hsets or local constants.
The new tests demonstrate new examples that can be handled by the
improved tactic in the HoTT library
2014-12-21 15:19:25 -08:00
Leonardo de Moura
70f7ec3cf2
test(tests/lean/hott): add test for 'cases' tactic
2014-12-20 11:36:32 -08:00
Leonardo de Moura
677ec2a2fe
feat(library/tactic/inversion_tactic): adjust inversion tactic to HoTT lib
2014-12-20 11:32:27 -08:00
Leonardo de Moura
2521dbb39e
refactor(hott): use same name convention for sigma in the HoTT and standard libraries
2014-12-19 18:46:06 -08:00
Leonardo de Moura
1e2fc54f2f
refactor(library/init/sigma): rename sigma.dpair->sigma.mk, sigma.dpr1->sigma.pr1, sigma.dpr2->sigma.pr2
2014-12-19 18:23:08 -08:00
Leonardo de Moura
9eea32b076
refactor(library/init/datatypes): change implicit arguments of sum.inl and sum.inr
2014-12-19 18:07:13 -08:00
Leonardo de Moura
07d7ea2f4e
refactor(frontends/lean/placeholder_elaborator): reduce coupling between placeholder_elaborator and frontends/lean
2014-12-19 15:08:21 -08:00
Leonardo de Moura
1797e2846f
fix(tests/lean/run): replace "open [notation]" with "open [notations]"
2014-12-17 18:28:38 -08:00
Leonardo de Moura
43633085b9
fix(tests/lean): adjust tests to recent changes in the lean libraries
2014-12-16 13:28:43 -08:00
Leonardo de Moura
86f3d029c7
test(tests/lean/extra): more tests for equations compiler
2014-12-15 19:22:17 -08:00
Leonardo de Moura
abe129aa4f
refactor(library): rename theorems "iff.flip_sign -> not_iff_not_of_iff" and "decidable_iff_equiv -> decidable_of_decidable_of_iff"
2014-12-15 19:17:51 -08:00
Leonardo de Moura
5cf8064269
refactor(library): rename exists_elim and exists_intro to exists.elim
...
and exists.intro
2014-12-15 19:07:38 -08:00
Jeremy Avigad
3e9a484851
refactor(library/logic/connectives): rename theorems
2014-12-15 15:05:44 -05:00
Leonardo de Moura
c6ebe9456e
feat(library/data/nat): add "bounded" quantifiers
...
Later, we will add support for arbitrary well-founded relations
2014-12-13 15:42:38 -08:00
Leonardo de Moura
f0b002d5a7
fix(library/aliases): aliases in sections and contexts
2014-12-13 14:57:15 -08:00
Leonardo de Moura
c291063f3a
fix(frontends/lean/structure_cmd): simplify structure names
2014-12-13 14:18:02 -08:00
Leonardo de Moura
c9365db41b
test(tests/lean/extra): more tests for equation elaborator
2014-12-12 15:43:41 -08:00
Leonardo de Moura
477d79ae47
refactor(library/init): move more theorems to logic
2014-12-12 13:50:53 -08:00
Leonardo de Moura
d6c8e23b03
refactor(library/init/logic): move theorems to library/logic
2014-12-12 13:24:17 -08:00
Leonardo de Moura
29aaa21f2a
fix(tests/lean/interactive): adjust test to reflect changes in the standard library
2014-12-11 19:53:41 -08:00
Leonardo de Moura
ab873cfff9
feat(frontends/lean/elaborator): replace metavariables in the equation lhs with fresh local constants before invoking compiler
2014-12-11 19:51:49 -08:00
Leonardo de Moura
b01cf73a91
feat(library/init/logic): add is_true and is_false
2014-12-11 18:14:03 -08:00