1 Introduction
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T is said to be a Browder contraction (BroC, for short) [3] if there exists \(\varphi\in\varPhi\) such that \(d(Tx,Ty) \leq\varphi\circ d(x,y)\) for any \(x,y \in X\).
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Considering the domain and range of θ and (θ1), it is obvious that (θ2) is equivalent to \(\inf \{ \theta(t) : t \in(0,\infty) \} = 1\).
2 Preliminaries
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S is said to be a Browder contraction if there exists \(\varphi\in\varPhi\) such thatfor any \(x \in Y\).$$ h(Sx) \leq\varphi\circ h(x) $$
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S is said to be a CJM contraction if the following hold:(j)For any \(\varepsilon> 0\), there exists \(\delta> 0\) such that \(h(x) < \varepsilon+ \delta\) implies \(h(Sx) \leq\varepsilon\).(jj)\(h(x) > 0 \) implies \(h(Sx) < h(x) \).
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There exists a sequence \(\{ u_{n} \}\) in \(\operatorname {Dom}(f)\) such that \(\{ u_{n} \}\) converges to t and \(\{ f(u_{n}) \}\) converges to γ.
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\(\limsup_{n} f(u_{n}) \leq\gamma\) holds for any sequence \(\{ u_{n} \}\) in \(\operatorname {Dom}(f)\) converging to t.
3 Browder contraction
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\(h(Sx) = 0\),
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\(h(Sx) > 0\).
4 CJM contraction
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\(\beta< \theta(\varepsilon+ \gamma) \) holds for any \(\gamma> 0\).
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There exists \(\delta_{2} > 0\) such that \(\beta= \theta(\varepsilon+ \delta_{2}) \).