Merge branch 'master' of github.com:naveensundarg/Spectra

README.md

@@ -0,0 +1,48 @@
+# Spectra
+
+Spectra is a general purpose planning system. It extends STRIPS-style planning by allowing arbitray first-order formulae for state descriptions and background knowledge rather than just predicates. This allows, for instance, handling domains with infinite or unbounded objects elegantly (among other things). 
+
+[Overview Presentation (pdf)](https://drive.google.com/open?id=1RHulFDgASACBkjvl-8ZEidj50NbGmKPu)
+
+ * Drawbacks of propositional planning (current planning systems): 
+ * **Expressivity**: Cannot express arbitrary constraints.  *“At every step make sure that no two blocks on the table have same color”*
+   * **Domain Size**: Scaling to large domains of arbitrary sizes poses difficulty. 
+
+## Spectra's Architecture ##
+
+ 
+![spectra-arch.png](https://bitbucket.org/repo/Mjq4bX/images/2495888298-spectra-arch.png)
+
+## Example Input File ##
+
+![examples.png](https://bitbucket.org/repo/Mjq4bX/images/3136509575-examples.png)
+
+
+ 
+## Scaling Up ##
+
+Two approaches: 
+
+1. **Procedural Attachments**: Special purpose procedural code that can bypass strict formal reasoning.
+
+2. *μ*-**methods**: Written in denotational proof language. Preserves soundness by letting us write down commonly used patterns of reasoning (a bit unwieldy integration now than the first approach)
+
+
+
+```clojure
+;; (removeFrom  ?x ?y) => "Remove ?x from ?y"
+;; (placeInside  ?x ?y) ==> "Place ?x inside ?y"
+(define-method planMethod [?b ?c ?d]
+  {:goal [(In ?b ?c) (In ?c ?d)]
+   :while [(In ?b ?d) (Empty ?c)
+           (< (size ?c) (size ?d))
+           (< (size ?b) (size ?c))]
+   :actions [(removeFrom  ?b ?d) (placeInside  ?b ?c) (placeInside  ?c ?d)]})
+```
+
+Roughly, a method has conditions that the goal and background + start state should satisfy. If the conditions are satisfied, a plan template is generated (note the variables).
+The planner then verifies if the plan template works, if so it outputs the plan. 
+
+## Spectra on a Seriated Cup Challenge ##
+
+![download-3.gif](https://bitbucket.org/repo/Mjq4bX/images/794008054-download-3.gif)

_config.yml

@@ -0,0 +1 @@
+theme: jekyll-theme-cayman