Loading [MathJax]/extensions/tex2jax.js
theorem Th1:
for
a,
b,
c being
Nat holds
(
c in seq (
a,
b) iff ( 1
+ a <= c &
c <= b + a ) )
theorem Th3:
for
a,
b being
Nat holds
(
b = 0 or
b + a in seq (
a,
b) )
theorem Th4:
for
a,
b1,
b2 being
Nat holds
(
b1 <= b2 iff
seq (
a,
b1)
c= seq (
a,
b2) )