Monday, October 13, 2014

Installing Z/EVES on Mac OS X

The following article is written by Andrius Velykis. The full link for the article is found below.

Z/EVES is an interactive theorem prover for Z notation. It can be used to develop Z specifications and reason about them. It has a number of attractive features, such as an easier learning curve (in comparison to related theorem provers, e.g. Isabelle), powerful proof tactics, and the ability to do proofs in Z notation.

Thursday, November 07, 2013

Isabelle Keyword Dictionary

Isabelle/Isar Reference Manual
For a comprehensive guide on Isabelle commands

declare thmsdeclares theorems to the current local theory context. No theorem binding is involved here, unlike theorems or lemmas (cf.§5.11), so declare only has the efect of applying attributes as included in the theorem speci cation. Isar manual p85

Locales - A sectioning concept for Isabelle
Locales are a means to de fine local scopes for the interactive proving process of the theorem prover Isabelle. They delimit a range in which fixed assumption are made, and theorems are proved that depend on these assumptions. A locale may also contain constants de fined locally and associated with pretty printing syntax. Locales can be seen as a simple form of modules. read more

Recursive Functions - Defining Recursive Functions in Isabelle/HOL
This tutorial describes the use of the new function package, which
provides general recursive function de nitions for Isabelle/HOL. We start
with very simple examples and then gradually move on to more advanced
topics such as manual termination proofs, nested recursion, partiality, tail
recursion and congruence rules. read tutorial

Tuesday, October 22, 2013

Change uuid of harddrive in VirtualBox

When you remove a hard disk from a Virtual PC you cannot put it back into the same Virtual PC. Hence you have to change the UUID of the hard disk before you can attach it to the same Virtual PC. You can do it by issuing the following command:

VBoxManage internalcommands sethduuid disk2.vdi 

Thursday, April 18, 2013

To enable NTFS copying and modification rights in Mac

Install NTFS-3G for Mac OS X 2010.10.2

Then, you should follow these steps in order to have the latest version of MacFuse:
1) Install - RESTART
2) Install - RESTART
3) Install

Now you have the latest version of MacFuse and the 64bit prefpane.

Link to original blogspot

Wordpress : “You do not have sufficient permissions to access this page” after you change database prefix

Have you changed the prefix of your database tables? I'm 90% sure, that this is your problem.
The thing is that WordPress uses the $table_prefix variable for forming the option and usermeta keys names, where it's storing the roles and capabilities information. So once you change the prefix, but don't update your db, you get this error. Here's how to fix it - execute this SQL command through phpMyAdmin, or a different interface for interacting with your DB(you can do it with PHP as well):
UPDATE `{%TABLE_PREFIX%}usermeta` SET `meta_key` = replace(`meta_key`, '{%OLD_TABLE_PREFIX%}', '{%NEW_TABLE_PREFIX%}');
UPDATE `{%TABLE_PREFIX%}options` SET `option_name` = replace(`option_name`, '{%OLD_TABLE_PREFIX%}', '{%NEW_TABLE_PREFIX%}');
  • {%TABLE_PREFIX%} is your current $table_prefix(as set in wp-config.php)
  • {%OLD_TABLE_PREFIX%} is your previous $table_prefix
  • {%NEW_TABLE_PREFIX%} is your new(current) $table_prefix - it will most-likely be the same as your {%TABLE_PREFIX%}.
So if your old $table_prefix was wp_test_ and your new one is wp_, you would do this query:
UPDATE `wp_usermeta` SET `meta_key` = replace(`meta_key`, 'wp_test_', 'wp_');
UPDATE `wp_options` SET `option_name` = replace(`option_name`, 'wp_test_', 'wp_');
Link to the Original Post!!!

Wednesday, March 20, 2013

Formal Logic Symbols

\models  double turnstile
In logic, the symbol \vDash or \models is called the double turnstile. It is closely related to the turnstile symbol \vdash, which has a single bar across the middle. It is often read as "entails", "models" or "is a semantic consequence of".

Thursday, February 28, 2013

How to Take a Screenshot in Mac OS X

How to Take a Screenshot in Mac OS X

How To Capture a Screen Shot with Mac OS X