diff --git a/prob_laplace.m b/prob_laplace.m
new file mode 100644
index 0000000000000000000000000000000000000000..ff8f03f50829915e6c7a9cbcacc6f6ac29b0b702
--- /dev/null
+++ b/prob_laplace.m
@@ -0,0 +1,16 @@
+%% Frank's solution to the transfer/rate problem via Laplace transform
+x0 = 1;
+p_out = @(D_p, D_m, ga, x0, x, t) 1./(2*sqrt(D_p*pi*t))*...
+            (exp(-(x+x0).^2./(4*D_p*t))*(ga*sqrt(D_p)-sqrt(D_m))./...
+            (ga*sqrt(D_p)+sqrt(D_m))+exp(-(x-x0).^2./(4*D_p*t)));
+p_in = @(D_p, D_m, ga, x0, x, t) 1./(sqrt(pi*t)*(sqrt(D_m)+ga*sqrt(D_p)))*...
+            exp(-(x-x0*sqrt(D_m/D_p)).^2/(4*D_m*t));
+x_in = linspace(-4, 0, 1000);
+x_out = linspace(0, 4, 1000);
+for i = 1:100
+    figure(1); hold on; cla;
+    plot(x_out, p_out(0.85, 0.15, 1/5.66, x0, x_out, i/10));
+    plot(x_in, p_in(0.85, 0.15, 1/5.66, x0, x_in, i/10));
+    axis([-4, 4, 0, 2]);
+    shg; pause();
+end
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