From f21bc5659d4f63f58ed5f46dbb85e4a81f68d69b Mon Sep 17 00:00:00 2001
From: Kamil Zabielski <50334623+limakzi@users.noreply.github.com>
Date: Thu, 5 Sep 2024 22:13:48 +0200
Subject: [PATCH] feat: Add IsFPFInduced properties (#89)

---
 lib/properties.gd                   | 29 +++++++++++++++++++++++++++++
 lib/properties.gi                   | 12 ++++++++++++
 tst/test_properties_magma_isfpf.tst | 19 +++++++++++++++++++
 3 files changed, 60 insertions(+)
 create mode 100644 tst/test_properties_magma_isfpf.tst

diff --git a/lib/properties.gd b/lib/properties.gd
index 2c18442..721476a 100644
--- a/lib/properties.gd
+++ b/lib/properties.gd
@@ -291,3 +291,32 @@ DeclareProperty( "IsRightCancellative", IsMagma );
 #! @EndExampleSession
 #!
 DeclareProperty( "IsCancellative", IsMagma );
+
+#! @Arguments M
+#! @Description
+#! is a left-hand sided fixed-point free inducted <A>m</A>.
+#!
+#! @BeginExampleSession
+#! gap> Display( MultiplicationTable( SmallAntimagma(2, 2) ) );
+#! [ [  2,  2 ],
+#!   [  1,  1 ] ]
+#! gap> IsLeftFPFInducted( SmallAntimagma(2, 2) ); 
+#! true
+#! @EndExampleSession
+#!
+DeclareProperty( "IsLeftFPFInducted", IsMagma );
+
+#! @Arguments M
+#! @Description
+#! is a right-hand sided fixed-point free inducted <A>m</A>.
+#!
+#! @BeginExampleSession
+#! gap> Display( MultiplicationTable( SmallAntimagma(2, 1) ) );
+#! [ [  2,  1 ],
+#!   [  2,  1 ] ]
+#! gap> IsRightFPFInducted( SmallAntimagma(2, 1) );            
+#! true
+#! @EndExampleSession
+#!
+#!
+DeclareProperty( "IsRightFPFInducted", IsMagma );
\ No newline at end of file
diff --git a/lib/properties.gi b/lib/properties.gi
index 4629df2..bc5f82e 100644
--- a/lib/properties.gi
+++ b/lib/properties.gi
@@ -59,6 +59,8 @@ InstallGlobalFunction(MagmaIsomorphismInvariantsMatch,
             Size,
             IsLeftCancellative,
             IsRightCancellative,
+            IsLeftFPFInducted,
+            IsRightFPFInducted,
             CommutativityIndex,
             AnticommutativityIndex,
             SquaresIndex,
@@ -230,4 +232,14 @@ end);
 InstallMethod(IsCancellative, "for a magma", [IsMagma],
     function(M)
         return IsLeftCancellative(M) and IsRightCancellative(M);
+end);
+
+InstallMethod(IsLeftFPFInducted, "for a magma", [IsMagma],
+    function(M)
+        return ForAll(M, m -> Size( Unique( m * Elements(M) ) ) = 1 and First( Unique( m * Elements(M) ) ) <> m);
+end);
+
+InstallMethod(IsRightFPFInducted, "for a magma", [IsMagma],
+    function(M)
+        return ForAll(M, m -> Size( Unique( Elements(M) * m ) ) = 1 and First( Unique( Elements(M) * m ) ) <> m);
 end);
\ No newline at end of file
diff --git a/tst/test_properties_magma_isfpf.tst b/tst/test_properties_magma_isfpf.tst
new file mode 100644
index 0000000..1e82301
--- /dev/null
+++ b/tst/test_properties_magma_isfpf.tst
@@ -0,0 +1,19 @@
+gap> START_TEST( "test_properties_magma_isfpf.tst" );
+
+gap> M := MagmaByMultiplicationTable([ [1, 1], [2, 2] ] );;
+gap> IsLeftFPFInducted(MagmaByMultiplicationTable([ [1, 1], [2, 2] ] ));
+false
+gap> IsRightFPFInducted(MagmaByMultiplicationTable([ [1, 1], [2, 2] ] ));
+false
+
+gap> M := SmallAntimagma(2, 1);      
+<magma with 2 generators>
+gap> IsLeftFPFInducted( M );
+false
+gap> IsRightFPFInducted( M );
+true
+
+gap> Filtered( Filtered(AllSmallAntimagmas([2 .. 3]), M -> IsLeftFPFInducted(M)), M -> IsRightFPFInducted(M) );
+[  ]
+
+gap> STOP_TEST( "test_properties_magma_isfpf.tst" );
\ No newline at end of file