From 5954c94350b0567e196b786605f68cf3fc0a8b90 Mon Sep 17 00:00:00 2001
From: "James D. Mitchell" <jdm3@st-andrews.ac.uk>
Date: Sun, 28 Jan 2024 20:17:11 +0000
Subject: [PATCH] Replace instances of "if X then return false; else return
 true; fi;" by "return not X;"

---
 lib/grp.gi      | 6 +-----
 lib/kernel.g    | 6 +-----
 lib/ratfun1.gi  | 6 +-----
 lib/straight.gi | 6 +-----
 4 files changed, 4 insertions(+), 20 deletions(-)

diff --git a/lib/grp.gi b/lib/grp.gi
index 267e920161..c70cb1b2db 100644
--- a/lib/grp.gi
+++ b/lib/grp.gi
@@ -2955,11 +2955,7 @@ local n,a;
   fi;
 
   a:=AutomorphismGroup(G);
-  if ForAny(GeneratorsOfGroup(a),i->Image(i,H)<>H) then
-    return false;
-  else
-    return true;
-  fi;
+  return not ForAny(GeneratorsOfGroup(a),i->Image(i,H)<>H);
 end );
 
 
diff --git a/lib/kernel.g b/lib/kernel.g
index 4a8937fd2e..ec171534d4 100644
--- a/lib/kernel.g
+++ b/lib/kernel.g
@@ -103,11 +103,7 @@ end;
 ##  </ManSection>
 ##
 IS_SUBSTRING := function( str, sub )
-  if LEN_LIST(sub) > 0 and POSITION_SUBSTRING(str, sub, 0) = fail then
-    return false;
-  else
-    return true;
-  fi;
+  return LEN_LIST(sub) = 0 or POSITION_SUBSTRING(str, sub, 0) <> fail;
 end;
 
 
diff --git a/lib/ratfun1.gi b/lib/ratfun1.gi
index 7264294815..448f7fcf88 100644
--- a/lib/ratfun1.gi
+++ b/lib/ratfun1.gi
@@ -635,11 +635,7 @@ local a,b,fam,i, j,ln,ld,rn,rd;
   od;
   # is there an a-remainder (then a is larger)
   # or are both polynomials equal?
-  if i>0 or i=j then
-    return false;
-  else
-    return true;
-  fi;
+  return not (i>0 or i=j);
 end );
 
 #############################################################################
diff --git a/lib/straight.gi b/lib/straight.gi
index efc54e1703..75fc2ad215 100644
--- a/lib/straight.gi
+++ b/lib/straight.gi
@@ -526,11 +526,7 @@ InstallMethod( IsInternallyConsistent,
 
       # If the number of generators is stored then check
       # that only defined positions are accessed.
-      if IsBound( nrgens ) and not IsSubset( defined, gens ) then
-        return false;
-      else
-        return true;
-      fi;
+      return not ( IsBound( nrgens ) and not IsSubset( defined, gens ) );
     end;
 
     len:= Length( lines );