Commit graph

270 commits

Author SHA1 Message Date
Jeremy Avigad
7c92161e49 refactor(library/data/finset/basic.lean): change order of arguments to induction tactic 2015-05-25 16:50:42 -07:00
Jeremy Avigad
8bebd104ff refactor(library/*): remove 'Module:' lines 2015-05-23 20:52:23 +10:00
Jeremy Avigad
db7bdce451 refactor(logic/funext.lean, algebra/function.lean): delete logic/funext, merge into algebra/function 2015-05-23 16:16:36 +10:00
Jeremy Avigad
d33c91d7b9 fix({hott,library}/algebra/*): fix names 2015-05-23 14:05:06 +10:00
Leonardo de Moura
e1c2340db2 fix(frontends/lean): consistent behavior for protected declarations
see https://github.com/leanprover/lean/issues/604#issuecomment-103265608

closes #609
2015-05-18 22:35:18 -07:00
Floris van Doorn
2144036cdb feat(hott.circle): prove that the fundamental group of the circle is equal to the integers, as groups
Also many minor fixes at various places
2015-05-18 15:59:55 -07:00
Leonardo de Moura
19361f0196 feat(library/unifier): do not fire type class resolution as last resort when type contains metavariables
see discussion at #604
2015-05-18 15:45:23 -07:00
Jeremy Avigad
566acf4b31 feat(library/data/finset/card.lean): add card_Union_of_disjoint and other theorems 2015-05-17 19:06:10 +10:00
Jeremy Avigad
6549940c63 feat(library/data/finset/bigops.lean): add Union for finsets 2015-05-17 17:50:32 +10:00
Jeremy Avigad
9720d84095 refactor(library/algebra/group_bigops.lean,library/data/nat/bigops.lean): add ext principle, clean up file 2015-05-17 16:00:38 +10:00
Jeremy Avigad
4764f6e8ec refactor(library/algebra/group_bigops.lean,library/data/nat/bigops.lean): simplify naming scheme for bigops 2015-05-17 15:24:37 +10:00
Jeremy Avigad
7bde8193fe feat(library/algebra/order): add alternate names for le.antisymm etc. 2015-05-17 12:54:36 +10:00
Jeremy Avigad
ff701a9812 feat(library/data/nat/bigops.lean): add finite products and sums for nat 2015-05-16 22:26:59 +10:00
Jeremy Avigad
eae047bd31 refactor,feat(library/{data,algebra}): move bigops to algebra, define sums 2015-05-16 18:42:13 +10:00
Jeremy Avigad
87e4f7a951 feat(library/algebra/group.lean): add coercions from additive (comm) monoid to (comm) monoid 2015-05-16 18:27:49 +10:00
Jeremy Avigad
daf53e4de2 fix(library/algebra/order.lean): rename decidable_eq to had_decidable_eq to avoid conflict 2015-05-16 17:53:35 +10:00
Jeremy Avigad
8de6a4bb4c feat(library/algebra/group_pow.lean,library/data/nat/power.lean): add generic power operation on monoids and groups 2015-05-13 22:19:02 -07:00
Floris van Doorn
0a8f4f6dab feat(function): add unfold hints to function.[h]lean 2015-05-07 16:39:03 -07:00
Leonardo de Moura
64cc710ff7 refactor(ordered_group): replace 'match' with 'obtain' 2015-05-06 10:34:43 -07:00
Leonardo de Moura
cd17618f4a refactor(library): replace 'calc_trans', 'calc_symm', 'calc_refl' and 'calc_subst' commands with attributes '[symm]', '[refl]', '[trans]' and '[subst]'
These attributes are used by the calc command.
They will also be used by tactics such as 'reflexivity', 'symmetry' and
'transitivity'.

See issue #500
2015-05-02 15:15:35 -07:00
Leonardo de Moura
3912bc24c8 feat(frontends/lean): nicer syntax for 'intros' 'reverts' and 'clears' 2015-04-30 11:00:39 -07:00
Leonardo de Moura
018f768555 chore(library): remove some unnecessary parentheses 2015-04-29 14:39:59 -07:00
Jeremy Avigad
7a1064b7e8 refactor(library/algebra/order.lean): rename a field in an order structure 2015-04-27 12:03:41 -07:00
Leonardo de Moura
670eac9d50 refactor(library): avoid 'context' command in the standard library 2015-04-21 19:13:19 -07:00
Jeremy Avigad
6359132b67 refactor(library/algebra/field.lean): rename has_decidable_eq and declare instance 2015-04-18 11:39:52 -07:00
Jeremy Avigad
5eb7fef564 feat(library/algebra/order.lean, data/int/{basic,order}.lean): add theorem, correct gt_trans 2015-04-18 11:39:52 -07:00
Leonardo de Moura
3b84a63874 fix(library/algebra/function): terminology 2015-04-16 20:52:18 -07:00
Leonardo de Moura
3df7fe120c feat(library/algebra/function): define curry and uncurry functions 2015-04-11 16:45:07 -07:00
Leonardo de Moura
5ba5e66665 feat(library/algebra/binary): add auxiliary theorems 2015-04-09 11:00:59 -07:00
Leonardo de Moura
d5176ebae5 refactor(library/algebra/binary): define right_commutative and left_commutative 2015-04-09 10:54:28 -07:00
Leonardo de Moura
754276a660 feat(frontends/lean): round parenthesis for [tactic1 | tactic2]
This commit also replaces the notation for divides
     `(` a `|` b `)`
with
      a `∣` b

The character `∣` is entered by typing \|

closes #516
2015-04-06 09:24:09 -07:00
Leonardo de Moura
4ec0e1b07c feat(frontends/lean): improve calc mode
Now, it automatically supports transitivity of the form
    (R a b) -> (b = c) -> R a c
    (a = b) -> (R b c) -> R a c

closes #507
2015-04-04 08:58:35 -07:00
Leonardo de Moura
3b0f666646 feat(library/algebra/function): define injective 2015-04-03 15:43:44 -07:00
Leonardo de Moura
ed1acd9fb0 feat(library/init): move propext to init/quot, add Jeremy's funext theorem 2015-04-01 12:36:33 -07:00
Leonardo de Moura
87f6fc6b6a feat(library/algebra/ring): remove sorrys 2015-03-30 11:55:48 -07:00
Leonardo de Moura
56af7ba535 feat(library/algebra/ordered_ring): remove sorry 2015-03-30 11:01:26 -07:00
Leonardo de Moura
75621df52b feat(frontends/lean): uniform notation for lists in tactics
closes #504
2015-03-27 17:54:48 -07:00
Rob Lewis
abcc56a2a7 feat(library/algebra):refactor field and ordered_field more appropriately 2015-03-27 11:54:11 -07:00
Rob Lewis
b79f600fbc style(library/algebra/ordered_field):fix indentation, shorten calc statements 2015-03-27 11:52:30 -07:00
Rob Lewis
94b9aaea45 feat(library/algebra/ordered_field): prove more theorems 2015-03-27 11:52:30 -07:00
Rob Lewis
a1028922bd feat(library/algebra/ordered_field): complete proofs of many theorems. Define discrete linear ordered field 2015-03-27 11:52:30 -07:00
Rob Lewis
4099de7754 feat(library/algebra/field): redefine field so that 1/0=0. Many theorems lose hypotheses in discrete setting. 2015-03-27 11:52:29 -07:00
Rob Lewis
365f1ebcb6 feat(library/algebra/ordered_field): prove more theorems for ordered field 2015-03-27 11:45:57 -07:00
Rob Lewis
11f82eacfb feat(library/algebra/ordered_field.lean): add ordered fields 2015-03-27 11:45:57 -07:00
Jeremy Avigad
765f6f21f8 fix(library/algebra/ring.lean): allow degenerate semirings and rings, but not degenerate ordered_semirings and ordered_rings. Closes #478. 2015-03-25 18:29:06 -07:00
Leonardo de Moura
14aeac180a refactor(library/algebra/category/constructions): more rewrite tactic tests 2015-03-12 20:27:11 -07:00
Leonardo de Moura
d7c6028a3e refactor(hott,library): use/test the rewrite tactic in more places
The performance also improved.
2015-03-12 17:25:31 -07:00
Leonardo de Moura
fa201bce9b feat(library/algebra/group): cleanup some proofs 2015-03-05 18:46:07 -08:00
Jeremy Avigad
c09f1c4eaf feat(*.md): create markdown files for HoTT library, update ones in standard library 2015-03-04 18:33:18 -08:00
Leonardo de Moura
6ad469e717 fix(library/algebra/order): duplicate argument 2015-03-03 17:04:26 -08:00
Leonardo de Moura
e2bef88a33 fix(library/algebra/order): duplicate arguments
There is a 'include s' in the section
2015-03-03 16:52:12 -08:00
Leonardo de Moura
b254c78c44 refactor(library/algebra): move bundled structures to separate module
Motivation: performance.
After this commit, the bundled instances do not participate in the
class/instance resolution if we do not import algebra.bundled.
2015-03-02 18:45:08 -08:00
Leonardo de Moura
a1066ebdf4 feat(library/algebra/ordered_group): improve performance using rewrite tactic 2015-03-01 11:38:27 -08:00
Leonardo de Moura
18ab9ce4e1 feat(library/algebra/ordered_ring): improve performance using rewrite tactic 2015-03-01 10:10:44 -08:00
Leonardo de Moura
9c0375b6e2 feat(library/init/logic): add transitivity theorems for = + <-> 2015-03-01 10:09:46 -08:00
Leonardo de Moura
25df44ea43 refactor(library/algebra/category/morphism): restore previous (and more readable) proofs 2015-03-01 06:54:52 -08:00
Rob Lewis
10f1232296 feat(library/algebra/field): fix broken theorems 2015-02-28 08:49:28 -08:00
Rob Lewis
8ef2849b67 feat(library/algebra/fields): prove more theorems about division rings 2015-02-28 08:49:28 -08:00
Jeremy Avigad
a8cf58d97c feat(library/algebra/field): define discrete field 2015-02-28 08:49:28 -08:00
Rob Lewis
eef2e99a1c feat(library/algebra/field): add theorems about division rings 2015-02-28 08:49:05 -08:00
Rob Lewis
b8f0341119 feat(library/algebra): add field.lean 2015-02-28 08:48:48 -08:00
Leonardo de Moura
3c24461e51 refactor(*): modify '|' binding power, use 'abs a' instead of '|a|', and '(a | b)' instead of 'a | b' 2015-02-25 15:18:21 -08:00
Leonardo de Moura
c04c610b7b feat(frontends/lean): add 'assert H : A, ...' as notation for 'have H [visible] : A, ...' 2015-02-25 14:30:42 -08:00
Jeremy Avigad
7a57908d62 feat/refactor(library/data/int): revise and add theorems 2015-02-25 14:05:07 -08:00
Jeremy Avigad
a607e7dd57 feat(library/algebra/group): add rules for sub equalities 2015-02-25 14:05:06 -08:00
Leonardo de Moura
577a6da119 refactor(library/algebra/category/morphism): reduce compilation time using rewrite tactic 2015-02-25 14:04:17 -08:00
Leonardo de Moura
4f79d12da7 refactor(library/algebra/category/morphism): improve performance using rewrite tactic 2015-02-24 18:28:49 -08:00
Leonardo de Moura
3ede8e9150 refactor(library): use [] binder annotation when declaring instances 2015-02-24 16:12:39 -08:00
Leonardo de Moura
3197e6d403 feat(frontends/lean/parse_rewrite_tactic): improve rewrite tactic parser 2015-02-23 19:40:03 -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
a35cce38b3 feat(frontends/lean): new semantics for "protected" declarations
closes #426
2015-02-11 14:09:25 -08:00
Leonardo de Moura
c7ee831c69 refactor(library/algebra/ordered_group): use rewrite tactic at ordered_group 2015-02-08 17:35:28 -08:00
Leonardo de Moura
f9ff4ee6bd refactor(library/algebra/ring): use rewrite tactic at ring module 2015-02-08 17:35:01 -08:00
Leonardo de Moura
d143b525f7 feat(library/algebra/ordered_group): reduce compilation time 2015-02-06 18:34:41 -08:00
Leonardo de Moura
96c161a659 feat(library/algebra/ring): simplify ring theorems using rewrite tactic 2015-02-05 18:48:02 -08:00
Leonardo de Moura
0ae6e2b3e4 feat(library/algebra/group): use rewrite tactic in the algebraic hierarchy 2015-02-05 18:03:02 -08:00
Leonardo de Moura
2ffdbba8b0 feat(library): replace same 'calc' proofs with 'rewrite' 2015-02-05 10:39:25 -08:00
Leonardo de Moura
7e5fb3e493 fix(library/algebra/function): remove notation that conflicts with top-level notation for dependent pairs 2015-02-01 11:35:01 -08:00
Jeremy Avigad
8d5a7a96b6 feat(library/data/nat/div): revise theorems, add lcm 2015-01-31 21:52:35 -08:00
Jeremy Avigad
928fc3ab81 feat(library/algebra/order,library/data/{nat,int}/order): make gt, ge reducible, add transitivity rules 2015-01-26 20:38:21 -05:00
Jeremy Avigad
85ef7c5151 refactor(library/algebra/group): rename neg_add_distrib to neg_add, etc. 2015-01-26 20:38:21 -05:00
Jeremy Avigad
ba15da8d83 refactor(library/init/reserved_notation): increase binding strength of ^-1 to max+10 2015-01-26 20:38:21 -05:00
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
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
ae7b5a9bc9 fix(library/algebra): add missing [reducible]
It addresses issues raised at #403
2015-01-21 15:53:56 -08:00
Jeremy Avigad
44642a4285 feat(library/algebra/ordered_ring,library/data/int/): add sign and theorems about abs, make int an instance, port theorems 2015-01-21 15:46:17 -08:00
Jeremy Avigad
58057c5d99 feat(library/algebra/ordered_group): add abs 2015-01-21 15:46:17 -08:00
Leonardo de Moura
abc64fbab8 refactor(library/algebra/group): remove unnecessary symm 2015-01-20 16:20:47 -08:00
Leonardo de Moura
8323d580b1 refactor(library/algebra/order): factor out proofs 2015-01-20 15:28:46 -08:00
Leonardo de Moura
21a3d918ff refactor(library/algebra/ordered_ring): use cleaner hack for improving performance 2015-01-19 17:41:11 -08:00
Leonardo de Moura
2717adde94 feat(library/unifier): add option 'unifier.conservative', use option by default in the calc_assistant 2015-01-19 16:23:29 -08:00
Leonardo de Moura
7149c49553 refactor(library/algebra): factor out proofs from coercions
Coercions/instances should be simple definitions
2015-01-19 13:00:24 -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
50fe085374 refactor(library/algebra/ordered_ring): using new structure instance syntax sugar to define instances 2015-01-16 18:01:08 -08:00
Leonardo de Moura
3d63c0b5dc refactor(library/algebra/ring): using new structure instance syntax sugar to define instance 2015-01-16 17:42:30 -08:00
Leonardo de Moura
a86661f42c refactor(library/algebra/ordered_group): using new structure instance syntax sugar to define instances 2015-01-16 17:37:08 -08:00
Leonardo de Moura
ebc1878028 refactor(library/algebra/group): using new structure instance syntax sugar to define instances 2015-01-16 17:23:41 -08:00
Jeremy Avigad
0dcf06000b refactor(library/data/int/sub): rename theorems, add theorems, clean up 2015-01-12 16:28:42 -05:00
Leonardo de Moura
2e4a2451e6 refactor(library/reducible): simplify reducible/irreducible semantics 2015-01-08 18:52:18 -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
Jeremy Avigad
cecabbb401 refactor(library/data/int,library/algebra): make int an instnance of ordered ring, rename theorems 2014-12-26 16:25:05 -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
5bc6dd84cf feat(library/data/nat): make nat an instance of comm_semiring 2014-12-23 21:14:35 -05:00
Jeremy Avigad
486bc321ff refactor(library/data/nat): rename theorems 2014-12-23 21:14:35 -05:00
Jeremy Avigad
6ad091d7bf refactor(library): clean up headers and markdown files 2014-12-22 15:33:42 -05:00
Jeremy Avigad
fe424add26 refactor(library/logic/axioms): rename theorems 2014-12-22 15:33:42 -05:00
Jeremy Avigad
0f0da64264 refactor(library/data/int): make int instance of integral domain 2014-12-22 15:33:42 -05:00
Jeremy Avigad
da7a403b6c refactor(library/algebra/ring): make dvd a definition 2014-12-22 15:33:41 -05:00
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
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
Jeremy Avigad
9d2587c79b refactor(library/data/int/basic): make the integers an instance of ring 2014-12-17 13:32:38 -05:00
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
628faa10eb refactor(library/algebra/ordered_ring): add workarounds to improve performance 2014-12-13 13:12:25 -08:00
Jeremy Avigad
6f775be1b6 feat(library/algebra/ordered_ring): start on ordered_ring, and minor changes elsewhere 2014-12-13 11:35:35 -08:00
Leonardo de Moura
d6c8e23b03 refactor(library/init/logic): move theorems to library/logic 2014-12-12 13:24:17 -08:00
Jakob von Raumer
63afac301c chore(library/hott): turn isomorphic into structure 2014-12-05 22:21:16 -08:00
Jakob von Raumer
6124b87870 fix(library/hott): adjust expliciteness of arguments 2014-12-05 22:20:51 -08:00
Jakob von Raumer
cda828bfe8 chore(library/algebra): change category to be a structure 2014-12-05 22:20:46 -08:00
Floris van Doorn
b62b4754cb feat(library/algebra): modify categories to use definitions, prove basic theorems about discrete categories 2014-12-03 20:29:16 -08:00
Jeremy Avigad
57effaf1a9 refactor(library/algebra): use new naming conventions, add information to speed up proofs 2014-12-02 12:14:14 -08:00
Jeremy Avigad
1bffd8dd21 refactor(library/algebra/order): change strong order pair, adopt new naming conventions 2014-12-02 12:14:14 -08:00
Leonardo de Moura
697d4359e3 refactor(library): add 'init' folder 2014-11-30 20:34:12 -08:00
Jeremy Avigad
a9001166fd fix(library/algebra/category/morphism): remove sorry that was introduced by accident 2014-11-28 22:54:15 -08:00
Jeremy Avigad
bb8d436e75 refactor(library/algebra/relation, library/logic/instances): revise equivalence relations and congruences to use structure command 2014-11-28 22:54:15 -08:00
Jeremy Avigad
7571f50870 feat(library/binary, library/relation): introduce general properties for binary operations and relations 2014-11-28 22:54:15 -08:00
Jeremy Avigad
89380f088e feat(library): reorganize and declare some notation 2014-11-28 22:54:15 -08:00
Jeremy Avigad
58e325f0af feat(library/algebra): add to developments of group, ordered_group, and ring 2014-11-28 22:54:15 -08:00
Leonardo de Moura
df51ba8b7c feat(library/definitional/projection): use strict implicit inference, closes #344 2014-11-25 18:04:06 -08:00
Jeremy Avigad
4420f0dc0c feat(library/algebra/group): add ordered semigroups 2014-11-17 18:32:14 -08:00
Jeremy Avigad
0d982cceed feat(library/algebra/ring): begin theory of semirings and rings 2014-11-14 17:27:35 -08:00
Jeremy Avigad
1ed7794264 feat(library/algebra/group): add theorems for calculation 2014-11-13 20:44:58 -08:00
Floris van Doorn
bf27a17dec style(library): add some comments 2014-11-08 19:12:54 -08:00
Floris van Doorn
8c7fdd3708 style(library): rename set_category to discrete_category 2014-11-08 19:12:54 -08:00
Floris van Doorn
930cc11684 doc(algebra): update markdown files 2014-11-08 19:12:54 -08:00
Floris van Doorn
cd33d2e96d refactor(typeof): move typeof to general_notation 2014-11-08 19:12:54 -08:00
Jeremy Avigad
4a955c0f92 feat(library/algebra/order): begin theory of orders
feat(library/algebra/order): begin theory of orders
2014-11-08 19:07:59 -08:00
Jeremy Avigad
c28227d7a1 feat(library/algebra/group): add multiplicative and additive structures 2014-11-07 10:23:37 -08:00
Leonardo de Moura
b177c84b06 feat(library/logic): add well-founded recursion
It also removes the old well-founded induction theorem based on
classical principles
2014-11-06 14:49:53 -08:00
Floris van Doorn
d8a616fa70 refactor(library): major changes in the library
I made some major changes in the library. I wanted to wait with pushing
until I had finished the formalization of the slice functor, but for
some reason that is very hard to formalize, requiring a lot of casts and
manipulation of casts. So I've not finished that yet.

Changes:

- in multiple files make more use of variables

- move dependent congr_arg theorems to logic.cast and proof them using heq (which doesn't involve nested inductions and fewer casts).

- prove some more theorems involving heq, e.g. hcongr_arg3 (which do not
  require piext)

- in theorems where casts are used in the statement use eq.rec_on
  instead of eq.drec_on

- in category split basic into basic, functor and natural_transformation

- change the definition of functor to use fully bundled
categories. @avigad: this means that the file semisimplicial.lean will
also need changes (but I'm quite sure nothing major).  You want to
define the fully bundled category Delta, and use only fully bundled
categories (type and ᵒᵖ are notations for the fully bundled
Type_category and Opposite if you open namespace category.ops). If you
want I can make the changes.

- lots of minor changes
2014-11-03 18:45:12 -08:00
Leonardo de Moura
4bdee07af2 refactor(library/algebra/category/basic): use calc assistant 2014-10-31 09:49:45 -07:00
Leonardo de Moura
e24225fabf feat(frontends/lean): validate infixl/infixr/postfix/prefix declarations against reserved notations 2014-10-21 15:39:47 -07:00
Leonardo de Moura
6c7e23ecaa refactor(library): use 'reserve' notation in the standard library 2014-10-21 15:39:47 -07:00
Leonardo de Moura
40fb66bf07 feat(frontends/lean): change default precedence to 1 2014-10-20 18:40:55 -07:00
Leonardo de Moura
4a9e725ca7 refactor(library/algebra/category/morphism): make sure bug #231 has been fixed 2014-10-13 20:56:40 -07:00
Leonardo de Moura
9edf780a00 feat(frontends/lean): elaborate inductive datatypes and introduction rules as a single elaboration problem 2014-10-13 18:35:11 -07:00
Leonardo de Moura
a26618e0f2 feat(frontends/lean): add '[]' notation for marking arguments where class-instance resolution should be applied 2014-10-12 13:06:00 -07:00
Leonardo de Moura
f832212fc8 refactor(library/algebra/category): remove unnecessary sections 2014-10-11 16:40:26 -07:00
Floris van Doorn
c630b5ddb2 feat(library/algebra/category): use variables instead of parameters 2014-10-11 16:40:18 -07:00