1 (* all outcommented in order to demonstrate authoring:
5 theory LogExp imports PolyEq begin
10 exp :: "real => real" ("E'_ ^^^ _" 80)
12 (*--------------------------------------------------*)
13 alog :: "[real, real] => real" ("_ log _" 90)
16 Solve'_log :: "[bool,real, bool list]
18 ("((Script Solve'_log (_ _=))//(_))" 9)
22 equality_pow: "0 < a ==> (l = r) = (a^^^l = a^^^r)"
23 (* this is what students ^^^^^^^... are told to do *)
24 equality_power: "((a log b) = c) = (a^^^(a log b) = a^^^c)"
25 exp_invers_log: "a^^^(a log b) = b"
32 (prep_pbt thy "pbl_test_equ_univ_log" [] e_pblID
33 (["logarithmic","univariate","equation"],
34 [("#Given",["equality e_e","solveFor v_v"]),
35 ("#Where",["matches ((?a log ?v_v) = ?b) e_e"]),
36 ("#Find" ,["solutions v_v'i'"]),
37 ("#With" ,["||(lhs (Subst (v'i', v_v) e_e) - " ^
38 " (rhs (Subst (v'i', v_v) e_e) || < eps)"])
40 PolyEq_prls, SOME "solve (e_e::bool, v_v)",
41 [["Equation","solve_log"]]));
46 (prep_met thy "met_equ_log" [] e_metID
47 (["Equation","solve_log"],
48 [("#Given" ,["equality e_e","solveFor v_v"]),
49 ("#Where" ,["matches ((?a log ?v_v) = ?b) e_e"]),
50 ("#Find" ,["solutions v_v'i'"])
52 {rew_ord'="termlessI",rls'=PolyEq_erls,srls=e_rls,prls=PolyEq_prls,
53 calc=[],crls=PolyEq_crls, nrls=norm_Rational},
54 "Script Solve_log (e_e::bool) (v_v::real) = " ^
55 "(let e_e = ((Rewrite equality_power False) @@ " ^
56 " (Rewrite exp_invers_log False) @@ " ^
57 " (Rewrite_Set norm_Poly False)) e_e " ^