let r be non-zero Sequence of REAL ; for p, s being Sequence
for alpha being Ordinal st alpha c= dom r holds
for x, y, z being Surreal st x <= y & y <= z & x in_meets_terms s,p,r,alpha & z in_meets_terms s,p,r,alpha holds
y in_meets_terms s,p,r,alpha
let p, s be Sequence; for alpha being Ordinal st alpha c= dom r holds
for x, y, z being Surreal st x <= y & y <= z & x in_meets_terms s,p,r,alpha & z in_meets_terms s,p,r,alpha holds
y in_meets_terms s,p,r,alpha
let alpha be Ordinal; ( alpha c= dom r implies for x, y, z being Surreal st x <= y & y <= z & x in_meets_terms s,p,r,alpha & z in_meets_terms s,p,r,alpha holds
y in_meets_terms s,p,r,alpha )
assume
alpha c= dom r
; for x, y, z being Surreal st x <= y & y <= z & x in_meets_terms s,p,r,alpha & z in_meets_terms s,p,r,alpha holds
y in_meets_terms s,p,r,alpha
let x, y, z be Surreal; ( x <= y & y <= z & x in_meets_terms s,p,r,alpha & z in_meets_terms s,p,r,alpha implies y in_meets_terms s,p,r,alpha )
assume A1:
( x <= y & y <= z & x in_meets_terms s,p,r,alpha & z in_meets_terms s,p,r,alpha )
; y in_meets_terms s,p,r,alpha
let beta be Ordinal; SURREALC:def 14 for sb, yb being Surreal st beta in alpha & sb = s . beta & yb = p . beta holds
y is sb,yb,r . beta _term
let sb, yb be Surreal; ( beta in alpha & sb = s . beta & yb = p . beta implies y is sb,yb,r . beta _term )
assume A2:
( beta in alpha & sb = s . beta & yb = p . beta )
; y is sb,yb,r . beta _term
( x is sb,yb,r . beta _term & z is sb,yb,r . beta _term )
by A1, A2;
hence
y is sb,yb,r . beta _term
by A1, Th74; verum