Example (23)
あるサイトに出ていた計算機による証明の課題です.
# prove (`!n. 1 + nsum (0..n) (\k. 2 EXP k) = 2 EXP (n + 1)`, INDUCT_TAC THENL [SIMP_TAC [NSUM_CLAUSES_NUMSEG; EXP; GSYM ADD1; MULT_CLAUSES; TWO]; ASM_SIMP_TAC [NSUM_CLAUSES_NUMSEG; LE_0; EXP; GSYM ADD1; ADD_AC; MULT_2]]);; val it : thm = |- !n. 1 + nsum (0..n) (\k. 2 EXP k) = 2 EXP (n + 1)