Dear Sir/Madam,

I have faced a problem while using Maple 18. The  warning is the following

Error, (in f) unable to store 'HFloat(1.9648999999999983)-HFloat(500.0)*delta' when datatype=float[8]
Error, (in plots/odeplot) input is not a valid dsolve/numeric solution

#` Part(a)`  deSh := diff(Sh(t),t) = (alpha(h)*Nh) +(omega*Rh(t))- (((betahb*Iv(t))/(Nh) +p+ mu(h))*Sh(t));   deEh :=  diff(Eh(t),t) =  (((betahb*Iv(t))/(Nh) )*Sh(t))-((mu(h)+gamm)*Eh(t));   deIh := diff(Ih(t),t) = (gamm*Eh(t))-(theta+mu(h)+delta)*Ih(t);  deRh := diff(Rh(t),t) = (delta*Ih(t))-((mu(h)+omega)*Rh(t));  deSv := diff(Sv(t),t) =  (alpha(m)*Nv*(1-Nw/(Nm)))-(((betamb*Ih(t))/(Nh) +mu(m))*Sv(t));  deEv:=diff(Ev(t),t) =  (((betamb*Ih(t))/(Nh) )*Sv(t))-((mu(m)+delta(m))*Ev(t));  deIv:= diff(Iv(t),t) = (delta(m)*Ev(t))-(mu(m)*Iv(t));   mu(h):= .000045 :   Nh:=5071126:  betahb:=.750:  p:=.09 :  omega:=.001:  alpha(h):=.5:  gamm:=.1667 :  delta :=.328833:  theta:= .0000002:  alpha(m) :=.1167:    Nv :=40570:  Nw:= 10000:  Nm:=50570:   betamb := .375 :  mu(m) := .02941:  delta(m):= .1428:     u:= .5:   F := dsolve( {deSh, deEh,deIh,deRh,deSv,deEv,deIv,  Sh(0)=8500,Eh(0)=100,Ih(0)=500,Rh(0)=0,Sv(0)=3500,Ev(0)=500,Iv(0)=570},     { Sh(t),Eh(t),Ih(t),Rh(t),Sv(t),Ev(t),Iv(t) } , numeric );  with(plots):  odeplot( F, [[t,Sh(t)],[t,Eh(t)] ,[t,Ih(t)],[t,Rh(t)],[t,Sv(t)],[t,Ev(t)],[t,Iv(t)]], t=0..30, numpoints=100, colour=[black,blue,purple, red,green,yellow,orange] , legend = ["suspectible host", "exposed host", "infected host", "recovered host","suspectible  vector","exposed vector"," infected vector"]);