diff --git a/README.md b/README.md
index 77e18d1d261b3bd5ce76b2e1679fc752a67640b9..01e694a7de1326e5f6053b2f8fc2848ee3c1fe79 100644
--- a/README.md
+++ b/README.md
@@ -22,4 +22,11 @@ This is a basic example which shows you how to solve a common problem:
 
 ``` r
 library(gmresls)
+# prepare a 4x3 toy problem Ax=b
+A=rbind(diag(1:3)+matrix(1, 3,3), rep(1, 3))
+xsol=1:3
+b=A%*%xsol
+f_Ax=function(x,...) list(...)$A%*%x
+f_Br=function(r,...) t(list(...)$A)%*%r
+x=gmresls(f_Ax, f_Br, b, A=A)
 ```