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                       A rough-and-ready guide to Igor2
                                   May 2008
                                   
                     Martin Hofmann and Emanuel Kitzelmann
                     
Contact:                     
	martin[dot]hofmann[at]uni[hyphen]bamberg[dot]de
	emanuel[dot]kitzelmann[at]uni[hyphen]bamberg[dot]de
	
Links:	
	http://www.cogsys.wiai.uni-bamberg.de/effalip/download.html
        http://www.inductive-programming.org/resources/systems/#igor2

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IGOR2 is free for evaluation, research and teaching purposes, but not for 
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##################
Remarks
##################


Thank you for being interested in IGOR2. This system is
part of ongoing research, so please neither expect a complete nor correct both
system not documentation. Sorry for that, but if you have questions or you need
support, we would be glad if you contacted as.

##################
IGOR2.2
##################

Let's get started:
-------------------

First you need to install the MAUDE interpreter from 

			http://maude.cs.uiuc.edu/
			
There you will also find any installation instructions you need.

Igor's code is shared between two directories, TermExtensions/ and IGOR2.2/. 
(The x is the (sub)version number. At the moment either 2 or 3) The file 
IGOR2.2/igor2.2.maude contains the main program. At the beginning all dependent 
file are loaded. They are referenced with absolute path names, so you'll need to
change them!

Maude modules are loaded into the interpreter with
	
	load 'filename'
	
So you do with igor2.2.maude and the file containing the example modules unless 
it has not been loaded automatically. Synthesis is started with the command:

        reduce in IGOR : setup('PROBLEM, 1, false) .
        
where the module PROBLEM contains a specification for IGOR. 'PROBLEM is its 
accordant module name in Maude's meta-language.

Problem Specification:
----------------------

The specification of a problem is Maude code, so please consult the Maude
manual for questions concerning the syntax. Note that a line must end with ' .'
(mind the space)! A specification module must define all used data types. The 
constructors, including used constants, must be labelled with '[ctor]'. 
The op-statement of the target function must be labelled with [metadata "induce"].
Other background functions are labelled with [metadata ""] or if they should be
used as predicates with [metadata "pred"]. If so, the are used as 
predicate *and* background function. If they should be used as predicates 
exclusively, use [metadata "pred nomatch"] 

Every target as well as every background function needs an op-statement
for a "dummy"-constructor. It has the same domain as the target/bk function, but 
a "dummy" sort as co-domain. This must also be included into the sorts-statement. 
normally this sort is called InVec.

Finally, the input/output examples are stated as equations.


The Solution:
-------------

The solution is a 'HypoList', so one or more hypotheses separated with 
'nextHypo'. If the hypothesis are semantically different, you should provide
more examples. Each hypothesis is a triple hypo(_,_,_). (The accordant data type 
is defined in the module FINISH in igor2.2.maude.) The first component
should always be 'true', denoting that the hypothesis is finished. the second 
component is a natural number stating the number of partitions the examples are
divided. The third is a list with (conditional) equations, the actual solution.
They all have the form 

       eq  LHS = RHS 		   or
       ceq LHS = RHS if Condition

The equations are in META-form.


##################
IGOR2.3
##################

Changes with respect to IGOR2.2:

	Setup:
		no path changes necessary
	Starting:
		reduce generalize('MODULE) .