diff --git a/MIL/C02_Basics/S05_Proving_Facts_about_Algebraic_Structures.lean b/MIL/C02_Basics/S05_Proving_Facts_about_Algebraic_Structures.lean index c4a0b24..4649313 100644 --- a/MIL/C02_Basics/S05_Proving_Facts_about_Algebraic_Structures.lean +++ b/MIL/C02_Basics/S05_Proving_Facts_about_Algebraic_Structures.lean @@ -157,8 +157,8 @@ Alternatively, you can use the ``trans`` tactic which takes ``y`` as an argument and produces the expected goals ``x ≤ y`` and ``y ≤ z``. Of course you can also avoid this issue by providing directly a full proof such as -``exact le_trans inf_le_left inf_le_right``, but this requires a lot more -planning. +``exact le_trans (inf_le_left : (x ⊓ y) ⊓ z ≤ x ⊓ y) (inf_le_right : x ⊓ y ≤ y)``; +but this requires a lot more planning. TEXT. -/ -- QUOTE: example : x ⊓ y = y ⊓ x := by diff --git a/MIL/C05_Elementary_Number_Theory/S04_More_Induction.lean b/MIL/C05_Elementary_Number_Theory/S04_More_Induction.lean index f83cd70..d506b82 100644 --- a/MIL/C05_Elementary_Number_Theory/S04_More_Induction.lean +++ b/MIL/C05_Elementary_Number_Theory/S04_More_Induction.lean @@ -105,7 +105,7 @@ example (n : ℕ) : fib (n + 2) = fib n + fib (n + 1) := by rw [fib] /- TEXT: Using Lean's notation for recursive functions, you can carry out proofs by induction on the natural numbers that mirror the recursive definition of ``fib``. -The following example provides an explicit formula for the nth Fibonacci number in terms of +The following example provides an explicit formula for the ``n``th Fibonacci number in terms of the golden mean, ``φ``, and its conjugate, ``φ'``. We have to tell Lean that we don't expect our definitions to generate code because the arithmetic operations on the real numbers are not computable.