1 files changed, 28 insertions, 0 deletions
diff --git a/lib/dihinf.c b/lib/dihinf.c
new file mode 100644
index 0000000..4f88a7a
--- /dev/null
+++ b/lib/dihinf.c
@@ -0,0 +1,28 @@
+
+#include "dihinf.h"
+
+dihinf_t *dihinf_compose(h_t g1i, const dihinf_t *g2) {
+  // we only need to consider the action of reflections
+  dihinf_t *g3 = (dihinf_t *)malloc(1 * sizeof(dihinf_t));
+
+  g3->r = !g2->r;
+  g3->i = g1i - g2->i;
+
+  return g3;
+}
+
+h_t dihinf_act(h_t gi, h_t s) {
+  // we only need to consider the action of reflections
+
+  return gi - s;
+}
+
+h_t dihinf_inverse_act(const dihinf_t *g, h_t s) {
+  if (g->r) {
+    return g->i - s;
+  } else {
+    return s - g->i;
+  }
+}
+
+