1 Structures A noun is an atom or a cell. An atom is any unsigned integer. A cell is an ordered pair of nouns. 2 Pseudocode [a b c] is [a [b c]]; *a is nock(a). Reductions match top-down. 3 Reductions ?[a b] 0 ?a 1 ^a (a + 1) =[a a] 0 =[a b] 1 /[1 a] a /[2 a b] a /[3 a b] b /[(a + a) b] /[2 /[a b]] /[(a + a + 1) b] /[3 /[a b]] *[a [b c] d] [*[a b c] *[a d]] *[a 0 b] /[b a] *[a 1 b] b *[a 2 b c] *[*[a b] *[a c]] *[a 3 b] ?*[a b] *[a 4 b] ^*[a b] *[a 5 b] =*[a b] *[a 6 b c d] *[a 2 [0 1] 2 [1 c d] [1 0] 2 [1 2 3] [1 0] 4 4 b] *[a 7 b c] *[a 2 b 1 c] *[a 8 b c] *[a 7 [7 b [0 1]] c] *[a 9 b c] *[a 8 b 2 [[7 [0 3] d] [0 5]] 0 5] *[a 10 b c] *[a 8 b 8 [7 [0 3] c] 0 2] *[a 11 b c] *[a 8 b 7 [0 3] c] *[a 12 b c] *[a [1 0] 1 c] ^[a b] ^[a b] =a =a /a /a *a *a