λδ digital library (LDDL)
Constant
![[butterfly]](http://helm.cs.unibo.it/lambdadelta/images/b5.png "\lambda\delta butterfly")
Informal description: ""
{λ[a:Prop].λ[b:Prop].λ[i:{((a).not).(b)}.iff]}.<{(b).(a)}.orec>.{({(i).(a).(b)}.th15).(a).(b)}.comorec Validation parameters: sort hierarchy = "Z2", kernel options = ""
Last update: Sat, 12 Dec 2020 10:46:54 +0100
![[Spacer]](http://helm.cs.unibo.it/lambdadelta/images/rainbow.png "\lambda\delta rainbow rule")
![[Generated from XML via XSL]](http://helm.cs.unibo.it/lambdadelta/images/xml_xsl2.png "Generated from XML via XSL")
![[PNG used here]](http://helm.cs.unibo.it/lambdadelta/images/PNGnow2.png "PNG used here")
![[Viewable with any browser]](http://www.anybrowser.org/campaign/bvgraphics/abtfile.png "Viewable with any browser")