cantor...

[helm.git] / helm / software / matita / nlibrary / topology / igft.ma

diff --git a/helm/software/matita/nlibrary/topology/igft.ma b/helm/software/matita/nlibrary/topology/igft.ma
index f4cf037a555adcb46eeb3a4f1fb3aad7ebdb3260..21194951bc91831f211012245fae1737f245f311 100644 (file)
--- a/helm/software/matita/nlibrary/topology/igft.ma
+++ b/helm/software/matita/nlibrary/topology/igft.ma
@@ -29,9 +29,9 @@ is coexisting with the old one in every development release
 (named "nightly builds" in the download page of Matita) 
 with a version strictly greater than 0.5.7.
 
-To read this tutorial in the HTML version, you need a decent browser
-equipped with a unicode capable font. Use the PDF version if some
-symbols are not correctly displayed.
+To read this tutorial in HTML format, you need a decent browser
+equipped with a unicode capable font. Use the PDF format if some
+symbols are not displayed correctly.
 
 Orienteering
 ------------
@@ -982,6 +982,8 @@ We now proceed with the proof of the infinity rule.
 D*)
 
 
+alias symbol "covers" = "new covers set".
+alias symbol "covers" = "new covers".
 alias symbol "covers" = "new covers set".
 ntheorem new_coverage_infinity:
   ∀A:nAx.∀U:Ω^A.∀a:A. (∃i:𝐈 a. 𝐈𝐦[𝐝 a i] ◃ U) → a ◃ U.