let L be non trivial Polish-language; for E being Polish-arity-function of L
for D being non empty set
for g being Polish-recursion-function of E,D
for K being Function of (Polish-WFF-set (L,E)),D
for t being Element of L
for F1, F2 being Polish-WFF of L,E st K is g -recursive & E . t = 2 holds
K . ((Polish-binOp (L,E,t)) . (F1,F2)) = g . (t,<*(K . F1),(K . F2)*>)
let E be Polish-arity-function of L; for D being non empty set
for g being Polish-recursion-function of E,D
for K being Function of (Polish-WFF-set (L,E)),D
for t being Element of L
for F1, F2 being Polish-WFF of L,E st K is g -recursive & E . t = 2 holds
K . ((Polish-binOp (L,E,t)) . (F1,F2)) = g . (t,<*(K . F1),(K . F2)*>)
let D be non empty set ; for g being Polish-recursion-function of E,D
for K being Function of (Polish-WFF-set (L,E)),D
for t being Element of L
for F1, F2 being Polish-WFF of L,E st K is g -recursive & E . t = 2 holds
K . ((Polish-binOp (L,E,t)) . (F1,F2)) = g . (t,<*(K . F1),(K . F2)*>)
let g be Polish-recursion-function of E,D; for K being Function of (Polish-WFF-set (L,E)),D
for t being Element of L
for F1, F2 being Polish-WFF of L,E st K is g -recursive & E . t = 2 holds
K . ((Polish-binOp (L,E,t)) . (F1,F2)) = g . (t,<*(K . F1),(K . F2)*>)
set W = Polish-WFF-set (L,E);
let K be Function of (Polish-WFF-set (L,E)),D; for t being Element of L
for F1, F2 being Polish-WFF of L,E st K is g -recursive & E . t = 2 holds
K . ((Polish-binOp (L,E,t)) . (F1,F2)) = g . (t,<*(K . F1),(K . F2)*>)
let t be Element of L; for F1, F2 being Polish-WFF of L,E st K is g -recursive & E . t = 2 holds
K . ((Polish-binOp (L,E,t)) . (F1,F2)) = g . (t,<*(K . F1),(K . F2)*>)
let F1, F2 be Polish-WFF of L,E; ( K is g -recursive & E . t = 2 implies K . ((Polish-binOp (L,E,t)) . (F1,F2)) = g . (t,<*(K . F1),(K . F2)*>) )
assume that
A1:
K is g -recursive
and
A2:
E . t = 2
; K . ((Polish-binOp (L,E,t)) . (F1,F2)) = g . (t,<*(K . F1),(K . F2)*>)
set G = (Polish-binOp (L,E,t)) . (F1,F2);
reconsider G1 = (Polish-binOp (L,E,t)) . (F1,F2) as Element of Polish-WFF-set (L,E) ;
Polish-WFF-args G1 = <*F1,F2*>
by A2, Th83;
then A5:
K * (Polish-WFF-args G1) = <*(K . F1),(K . F2)*>
by FINSEQ_2:36;
thus K . ((Polish-binOp (L,E,t)) . (F1,F2)) =
g . [(L -head G1),(K * (Polish-WFF-args G1))]
by A1
.=
g . [t,(K * (Polish-WFF-args G1))]
by A2, Th83
.=
g . (t,<*(K . F1),(K . F2)*>)
by A5, BINOP_1:def 1
; verum