added preconditions

Author: AYadrov

bench/physics/kalman.fpcore

@@ -1,5 +1,6 @@
 (FPCore (dt r)
         :name "Kalman filter per K"
+        :pre (and (< 0 dt) (< r 0))
         ; initializing matrices
         (let ([p00 25.0]
               [p01 0.0]
@@ -68,6 +69,7 @@
 
 (FPCore (x0 x1 x2 dt r sensor)
         :name "Kalman filter per x"
+        :pre (and (< 0 dt) (< r 0) (< 0 sensor))
         ; initializing matrices
         (let ([p00 25.0]
               [p01 0.0]
@@ -145,6 +147,7 @@
 
 (FPCore (dt r)
         :name "Kalman filter per P"
+        :pre (and (< 0 dt) (< r 0))
         ; initializing matrices
         (let ([p00 25.0]
               [p01 0.0]